the SAMOLOED is very impressive when it comes to depth, contrast, detail, etc..
I really miss looking at the screen on my Epic.. however, (if you're only comparing screens).. the Photon screen is pretty damn good.. I can see it in bright sunlight w/ sunglasses on. it doesn't look grainy, i notice that while scrolling, it seems to 'dim' a little bit but this might be a characteristic of the pentile display.. colors look just fine (although, to be fair, I'm color blind

).. If you're looking for a Hi-Def TV... go get one. this is a damn phone LMFAO.
The screen is better than the Evo 3D FWIW...
now, to be fair, you should also compare the other aspects of the devices to make an informed decision.. the GPS works on photon/flaky on Epic.. same for bluetooth. the 3G radio on Photon works really well and is fairly quick (compared to the Epic).. bluetooth just works on photon/flaky on epic. battery life on photon is disgustingly good (is that a word ?? LOL).. Epic = mediocre..
to be fair, I have SRF 1.2 on my Epic and I love that device.. I just don't have any complaints (yet) w/ the photon and I've had it a week
I hope this helps