Speed: Mede8er 500x or any Realtek-based player.
Features: PCH210/A200 (highly proven and matured), S800 (potentially similar because of Sigma - it looks very good on paper for me, and based on initial impressions by owner and seller). There are some playback features of the PCH that the Mede8er (and many other Realtek players) appear to be incapable of. The new Egreat might be equally capable as well - pending actual tests.
FW Maturity: PCH210/A200. Always ahead of the pack. Mede8er is pretty good too in the Realtek side - always tried to be copied by other brands using the same OEMs. Egreat - see below.
NMJ/Wall Paper: Whichever you choose, you need some work and time to make the GUI eye-candy. The PCH210/A200 should be the most advanced because it's the most matured. NMJ is not really difficult provided your file system is prepared well, and again, depending on how much data you have, you definitely need lots of time and patience. Ang masakit neto, once you have set-up your jukebox well, you'd realize it's a huge burden on the player itself - in short, mabagal ang response. The Mede8er is getting there (compared to other Realtek Players, arguably the most matured and consistently on top of the list of the best NMTs - bested only by the PCH-A210/A200). S800 being the youngest has great potential because of its Sigma chip..BUT, and there is a big BUT
based on my 31B experience with the Egreat (and yours too Anchit), Egreat totally sucked big time in terms of FW development and upgrade. Hope they have improved. Some people claim there is no need to upgrade on FW. Fair enough. But if that is the case, then why the hell did/do makers keep on releasing FW updates? In any case, the R200 is looking very good indeed, and the S series models are looking even better - pending more feedback from actual PDVD users, the popular international player boards (and hopefully based on future actual personal tests).
File Management: You really want to transfer TBs of data from any player directly to an external HDD and vise versa? Pasang awa ang Mede8er and PCH compared to a PC (and that is being too kind), but I don't know about the Egreat. The bare SATA interface may be better. But I think the golden rule in terms of file management is, stick with a PC.
Network: I find it just as easy to use the Mede8er as the PCH on a network (wired - I never bother about Wi-Fi so can't comment about that). I dont know about the Egreat but I don't expect it to be any different.
3D: Anybody cares about this feature? PCH is supposed to be capable of Half-SBS already. Unfortunately, I haven't met anyone who owns all the required hardware. I think Boss Vic of SnS has got all the hardware.
Pogi/Cool Factor: It appears to be a no contest in favor of the Egreat designs.