From what I've read - performance between the two shouldn't matter - after the initial login. Odex should be faster but I ran Odex for awhile (4.4.2) and didn't notice any difference between that and after getting Baja 4.4.2 (deodex). Battery life is a lot better for me on Baja 4.4.2 (deodex) than it ever was on Odex 4.4.2.... but that's comparing apples to oranges I think as Baja might have rom optimizations that weren't in the stock Odex 4.4.2.
If you theme at ALL - Deodex is a must. (I never theme but I've been really happy with Baja 4.4.2 so I'm changing my mind on that...).