If you still have a large collection of 1080p Blu-ray discs, and I assume you do, the X1100ES gives you the option to upscale internally via the player, or pass 1080p along to your AVR or display. Compared to the upscaling on my LG B8 OLED television, I routinely found the upscaling quality of the X1100ES to be superior. I found the X1100ES's upscaling retained and revealed more detail within the image as compared with my television's upscaler, and objective testing with some test patterns confirmed this. The image also seemed to possess a more natural appearance thanks to the player's lack of ringing artifacts commonly introduced when an upscaler artificially sharpens the image. Unless you have a fairly high-end video processing solution available, I'd recommend using the X1100ES's built in upscaler for your sub-4K video content.
While testing for video upscaling quality, I also ran the player through the usual objective tests for chroma upscaling and deinterlacing. Deinterlacing performance was top notch and, while not the best I've seen at this price point, chroma upscaling quality should be good enough for all but the pickiest of videophiles.
As with the rest of Sony's 2019 Ultra HD Blu-ray player lineup, playback of Dolby Vision-encoded video is one of the main selling points of the X1100ES. No matter where the content came from, be it discs or streaming, Dolby Vision content was a consistent upgrade in video quality. The Dolby Vision streams of Stranger Things and Lost in Space via Netflix had a greater sense of dynamic range, more natural appearing colors, and better shadow detail.
One additional issue I noticed when playing Dolby Vision content, though, was that the player doesn't seem to be sending the proper REC2020 color gamut flag. With stock HDR10 content, the X1100ES does. Whether or not this will cause an issue with color point mapping on a display remains to be seen. As far as I know, all Dolby Vision content is mastered to REC2020, so if a display knows the content is Dolby Vision, it should also know to map colors to a REC2020 gamut. The Panasonic Ultra HD Blu-ray players that I've had here recently, by comparison, correctly sends this flag with Dolby Vision content, so I believe this omission or bug is worth pointing out.
The X1100ES offers HDR-to-SDR conversion when the player detects it's connected to a display that lacks HDR support. When this happens, an additional menu item appears that allows you to adjust the tonemap to better suit the brightness capabilities of the connected display. The lower you set the tonemap, reducing the dynamic range more, the brighter in appearance the video becomes. Overall, the performance was generally good, but not great, in my testing. The tonemapping did have a slight tendency to oversaturate colors when converting the color points from REC2020 to REC709 and, on occasion, crushed some shadow detail in darker scenes. I also noticed that high-nit portions of the image had a tendency to clip, something I didn't notice as often from competing players that offer HDR-to-SDR conversion. I don't think many purchasing the X1100ES with use this feature, but it's handy to have in a pinch when you're stuck with an older non-HDR display and only have an HDR10 version of a film or television show.
During my time with the X1100ES, I streamed a lot of video files stored on my desktop PC over my home network. While the user interface for the media player app needs a facelift to bring it into the twenty-first century, playback of both audio and video files worked better than expected. High-bitrate 1080p H.264 and 4K HDR10 HEVC files worked without issue. Video quality seemed to mimic that of disc-based video playback. However, with high-bitrate content, I would avoid using the player's Wifi connection as it tended to have buffering issues. Swapping over to the wired LAN port, or playing back the file from the USB port, solved this issue.
The biggest downside of the X1100ES are the tonemapping options available or, I should say, the lack thereof. Unlike competing players from brands such as Panasonic, with its HDR Optimiser tool, you're limited to tonemapping content down to SDR only, and that's only if the connected display doesn't support HDR. Neither HDR-capable OLED televisions nor projectors meet the brightness standards needed to faithfully reproduce the vast majority of HDR content. In particular, high-nit specular highlights cannot be faithfully reproduced on these types of displays. Typical examples of content with high-nit specular highlights would be a bright sunset in the background of a shot or a bright spotlight in a dark scene. Without the brightness needed to reproduce these types of shots, you'll often get a blown-out, clipped highlight, devoid of detail that's supposed to be present in the image.
To fix this issue on a display without the brightness to faithfully reproduce these shots, you need to tonemap the content and this can be problematic for two reasons. First is that most players lack a tonemap mode to fix this specific issue, like with the X1100ES. Secondly, this means you're left with your display's built in controls or automated tonemapping to correct such issues, and not all displays come with controls to fix this. For LG OLED owners, you do have the option to help correct this issue, but the fix comes with a global reduction in luminance, which is the opposite effect that we want for HDR content.
What competing players from Panasonic do is apply a light tonemap that targets just the high-nit portion of an image, above 600 nits for example if you're using an OLED television, and reduces the dynamic range to avoid blown out highlights and brings back detail within that part of the image that would otherwise be lost without the tonemap being applied, all without a reduction in overall luminance. The Panasonic players also change the static HDR10 metadata sent to your display to reflect the new peak nit point, 600 nits in this example, so your display doesn't apply a second, redundant, tonemap to the image. At the X1100ES' price point, I would have expected to see something comparable to what Panasonic has been offering for a number of years now.
It also bears repeating that Dolby Vision is not auto-detected and must be turned on manually. That's a big oversight for any disc player in 2019 and outright criminal at this price point.
Competition and Comparisons
As I alluded to above, the X1100ES has some serious competition from Panasonic, specifically from their DP-UB820. This player is currently priced at $499, making it $100 cheaper than the X1100ES. While the X1100ES does offer more flexibility with system control and disc playback compatibility, the UB820 offers far more flexibility in what it can do with an HDR10 image. The UB820 also supports HDR10+, making it one of only a handful of players currently available that supports all four major HDR standards.
Additionally, the UB820 has 7.1 analog audio outputs, compared to the stereo outputs on the X1100ES, giving owners more flexibility in how they can set up their home theater. If you plan on watching a lot of HDR10, which is what all Ultra HD Blu-ray discs have at a minimum, I do think image quality on the UB820 is superior due to its HDR Optimizer tool, of which the X1100ES lacks an equivalent. Unless you need IP control capabilities or SACD support, I think the UB820 offers more value.
Sony's own UBP-X800M2 (reviewed here) is a similar story. In many ways, it's the same player as the X1100ES, but at half the cost. You're giving up some system integration abilities, analog audio outputs, an information screen, and two years off the warranty, but, if you can live without all of this, it's easy to recommend the X800M2 over the X1100ES.
Sony's UBP-X1100ES is a solid choice for those who are already invested in Sony's ecosystem. The included Bravia and LDAC Bluetooth modes offer loyal Sony customers a way to get the best audio and video quality from this player. It's also a great choice for those looking for a player that's easy to integrate within their home theater control system.
The X1100ES also offers an impressive range of compatibility with both discs and file-based playback methods too. However, I do think those looking for a more refined HDR experience from a projector or OLED television, or a player that offers more value, should look elsewhere. With that said, those comfortable with a stock HDR experience, or with a way to curtail the image for their display outside the player, should be happy with the X1100ES.