Unless it has the lieflat config as noted above, the 757 and 737 are very comparable in F (and in Y for that matter, although there are a few more "good seats" on a 757 - especially a 753 - than on a 739). The key thing is to avoid the bulkhead on either as they are both cramped.

If the prices were equal, I would consider the 757 if only because the pre-departure experience is nicer because of the "turn left" - more likely to get PDB, your coat hung, etc. But I'd put that at a $25 preference - not a $200 one. And, as others noted, schedule should probably be your #1 priority.