I am glad Mark isn't bothered by the noticeable gloss differential on Luster/gloss papers and says that you would have to be looking at prints from unusual angles to see it. He's correct to say it isn't noticed when looking at a print from dead center but not all prints are viewed from center as in crowded galleries.Sadly gloss differential does reveal the weakness in a printer not being able to uniformly coat an image and hopefully manufacturers aren't given a pass to not improve on this problem. Epson acknowledges gloss differential as an issue and strives to correct for it. In one printer they included an extra cartridge called the gloss optimizer to remedy the problem.
Mark also gave Epson a pass on the poorly designed and constructed rear paper support that lets paper flop backwards because the back support doesn't telescope high enough. He is right that the paper feed still works but I find this an excuse for a poor design which should be improved on. Epson should correct it and give us a similar rear back paper support as they put on the P800.
On the gloss differential business I maintain my position based on what I see. What I see depends on the kind of paper and the angle of view. On a textured luster paper such effects would be far less evident than on a smooth semi-gloss or finely textured luster, but this also depends on the photo. For smooth or smoothish papers, viewing the print at an angle unusual enough not to be able to appreciate the photo, one may notice some in non-inked areas looking hard enough for it. On the more heavily textured luster papers such as Hahnemuhle Photo Rag Baryta, I just don't see it, either from the Canon or the Epson printers I've been testing lately. It isn't for me to give manufacturers a "pass" - I just report what I see, my vision is pretty good and I've been examining prints over decades....
Turning to the paper support for the SC-P5000, again, sorry, but in my humble opinion, this is a non-issue. You may have noticed that if the paper is flexible enough to bend backwards, it may rest on the roll holder cover behind the paper support; otherwise it may just bend backward a bit. That's fine. I have yet to load a sheet into that printer (and I've loaded plenty of different characteristics) that is the least bit affected by the paper support arrangement. The day it fails to pull the paper through correctly on account of this construct, I'll let you know. Again, not an issue of giving manufacturers a "pass". I simply report my findings.
You don't agree with them, that's fine. You are of course entitled.