Epic super amoled screen + physical keyboard EVO bigger screen + better community support for rooting, with Swype, I don' t envy physical keyboard anymore.
I have both phones (company owned, not from my own pocket), here is my take on EPIC vs. EVO: EPIC's cpu+gpu is indeed more powerful than EVO, and it's amoled screen is very shiny and colorful. However, I don't like reading text using EPIC since I can clearly see the dots in the texture, while EVO provides a much more "smooth" reading experience. Plus, the Samsung software has a lot of small problems, and is slow in updating while EVO is catching fast with Android's release. Also, the 4G on Epic is not stable, the connection comes and goes constantly even under good channel conditions while EVO could provide a constant connection all the time. Noticebly, the Wifi on Epic is worse than that on EVO. Last but not least, the Epic feels cheap than EVO. Just my two cents.