The 3-4-2 section has wider seats and better legroom at 32-33".

The back section is horrible with 3-4-3 and 31-32".

That being said, I have never been stuck in the back with status (well, took the bulkhead once - terrible), but you can only get seats assigned in rows 21-30 if the class is high enough. YBHKMLVX or something. I know for sure that NQOAG etc get only the crappy seats. AY used to accommodate my requests as an AA Plat but no more.