For all the things u have listed as your requirement, the 6300 fits the bill perfectly...it has a better display at 16m color and has no problems with font size..cam is again 2 mp as compared to 1.3 in E50...even though its better than E50's cam, its not a very good one (infact worse than 6233 in pic quality)...
Sound again is very good thru the headphones as well as the speaker..E50's sound is a bit less in comparison especially thru the loudspeakers..it has FM while E50 doesnt(if tht matters to u)..
The only thing going for E50 is tht its symbian and you can have third party apps for it...but then again, all tht depends on ur needs...if u want a phone for good sound, cam quality and display, its the 6300 all the way...
If u want a cheap smartphone, its the E50...neways, it doesnt seem tht smart enuf..
Also appearance wise, the 6300 wins hands down....its metal casing is top class...although i find it a bit girly(but thts just me..

no offense) I think the 6300 is what u shud go for...
