hi,
first i have to say i was just here to say "yeeeeeaaaaahhhhh", thanks and all that sort of things

for the fresh Revo GA release !!!
now, to answer your question, i must say that for what i’ve seen, your choice between Revo and Evo should not depend on your php abilities as both will serve you the same easyness (don’t know if the word exists...) without a great php knowledge.
The only thing that could be important for you is that, for the moment, there are more "third party" components available for Evo and, if you don’t plan to write your owns, of course, this could help you build more complex things. But, according to how fast people are here... i’m sure this will soon change and you’ll soon get nearly everything you need in terms of snippets, plugins and so on for Revo.
Hope it’ll help and, once more, Yeeeeaaaaahhhhh
Have swing