As an Epson 5040 owner, I can say that the biggest issue with Epson right now is lack of 18gbps hdmi.
Here is what it means in the real world:
- Netflix - I haven't an issue with HDR content. It runs at 30hz, so perhaps the Shield I use to play it is cutting frame rate in half.. ? Not sure, but I can for sure get HDR at 30hz.
- PS Vue - have to run in Rec709. If I run in BT2020 I can only get 30hz, and it starts dropping frames after a few seconds, to the point where you get about 3 frames per second, sometimes less. No issues in Rec709, but with a Shield it means manually changing the color space back to Rec709.
- Blu Ray - Movies filmed at 24 or 23.976 hz will play just fine with BT2020 color. However, motion (at 4k) is not great. A little smoothing here would go a long way. I notice a difference between when I am at BT2020 color and 30hz max vs Rec709 and 60hz max. The Rec709 mode allows the projector to double the frame rate for a slightly smoother image.
- UHD - Again, any wider color gamut comes with the caveat of lower frame rate. Usually not a huge deal outside of Netflix UHD and gaming, but when used with a Shield, it means manually switching color spaces a lot (you can't just leave it in BT2020 mode).
Color is very brilliant with the Epson, as mentioned, but a little too hot without calibration. I was much happier with my last Sony in terms of color out of the box. But without calibration, you get a lot more lumens than either other brand, so if you have a bigger screen it is helpful. This is a tradeoff between color accuracy and brightness. It isn't BAD per se, but skin tones can get a little too red or green depending on the source. Often I wonder if all actors spent too much time in the sun before shooting, they can look perpetually sun burnt. But most of the time the Epson looks fantastic.
4k vs e-shift: IMHO I don't think this is a big deal. In static images, like running a PC on the projector, the true 4k would be better, but for moving images, it just doesn't seem to matter. I am VERY happy with the sharpness and clarity of 4k on a 150" wide scope screen. Any more sharpness would be lost on me, sitting 13 feet back from this rather large screen. For people with smaller screens, I can't see spending the extra money on native 4k. So this becomes an e-peen thing (I have native 4k so I am better than you)
Lamps - as mentioned, lamps are 2-3 times more from JVC. This is a big deal when you have a bigger screen and have to run in high lamp. If I have to replace my lamp twice a year, I would rather spend $300-400 vs $800-1000.
Contrast - I'm happy with my contrast, but I am not overly concerned with black levels. At least it is not worth 2-3 times more just for slightly better blacks. I also think this is a relative issue. I started with a DLP, and then went to a Sony and saw a major improvement in contrast. Then I went to the Epson, and it seems just as good if not better than the Sony. So I'm good with what I have. The blacks are as good as my flat screens when the room is blacked out, but I also don't own an OLED. So my point of reference is not on the extreme edge.
Frankly, I will probably sell my 5040 when the 5050 comes out just for the 18gbps hdmi. This is a major thorn in my side. I use ONLY the NVidia Shield as my source for all my media, and since it won't automatically change color spaces, I have to manually switch depending on content. And even if I didn't, I just want to get the full color range no matter the framerate. It seems minor but it is just a major annoyance factor. Gaining the better e-shift, a better tone map for HDR, and a few other little things are all nice, but the real value for me is the HDMI spec.
But I am also looking at JVC. Three times the price for the one I am looking at compared to the Epson and while it is a stretch to justify it, the JVC is the "next level up". Better blacks, some motion smoothing, better lens, etc. It is really like going from a good LCD flatscreen to an OLED (minus the brightness of course). And if I decide to add an anamorphic lens later, it can do most of the image processing to allow me to get rid of black bars and do the stretching. Really the thing holding me back is cost. The Epson will be around $3k, the JVC around $7k, and if I add a lens, another $4k. Even in a $50k theater, that is a big gap and a monster stretch, especially since I already spent my budget. Add another $1000 per year in lamps and the incremental differences just don't seem worth it. I'm still on the fence myself, but leaning toward the Epson 5050.