What's better for the old style rock and for vocals odin or evo?
not sure about the answer, as other have already said it will heavily depends on your library. but one thing I know for sure: you must listen to both before buying. both have this "peculiar" EE pinna gain, and if you are sensitive in that area, it will be a big (BIG) problem.
personally, I was going to buy Odin, had my card ready, but after having listened to both I decided for the EVO, basically for two reasons: 1. they fit better in my current IEM collection and 2. Odin is more linear in the bass region, and this in turn will enhance even more the pinna gain perception
for point 2. it is important to understand "where" in the fr you point your comfortable listening volume. if, say, you need a certain amount of bass to enjoy your music, and set the overall volume to reach that level, with EVO the mids and treble will be much lower than with Odin. something like:
while if you set your listening level on the mids, you will get much (MUCH) more basses and lower treble with the EVO, something like this:
I'm not saying one or the other is wrong, it will depend on your taste and library. I have preferred the EVO because I want a full bass foundation when I listen to music, but I suffer a lot from too enhanced upper mids. but of course this also means that central mids are fairly recessed.
as usual YMMV, unfortunately with this kind of very "personal" tuning the only way is to listen for yourself, every ear is different.
all of the above is of course just IMHO