IMHO, at this point, if you know you'll be in Y, then the E-170 is the best Conited narrowbody, at least as far as seat size and comfort. That's scary, but with the hard benches on the 737s and CO 757s, the simple oldness of the UA 757s and the Recaro torture thrones coming in on the Airbuses, a lowly E-170 is tops. Unless you can grab an Airbus with the old seats, and then pray that they don't swap equipment between the time you book and the time you fly.
Strangely, I find the F seats on an E-170 to be not that great. They stink on the CR-7s, although they're better than coach on those birds.