Funny you should mention that, blink. I flew out to SFO (Flight 1277) on July 19 and was in 15F. Coming back on July 30 (Flight 1476) I was in 12F, too, and it seemed like there was more legroom in row 12. I remember the lady in 12E was already seated when I got there and she didn't even have to get up to let me in.
Both 757's on my trip were also in the old interior, although the MD80's between AUS-DFW were in the new.
The one thing I noticed about the window seats on the 757's was that it was kind of hard to see the video screens without leaning over toward the person in the middle seat. The overhead compartments block out the upper right or left hand corners depending on which side of the plane you are seated on. Then again, I'd already seen the episodes of Everybody Loves Raymond so I listened to music instead.