I think depending on if it's a new gun or not, there may be slide-weight differences... The original 226's with stamped slide was actually a little lighter than the 229 even being a shorter pistol. Without checking width specs I'd bet the 229 is basically just a shorter version of the same gun with slightly shorter grip as well. If either grip fits you well, it's a toss-up, I'd say.
I can say my non-rail CPO p226 shoots like a dream, and though the stock grips could be improved upon, I found it fits me perfectly. If the 229 shoots as well, and I'll bet it does, either would be a great great gun.