I sat in orchestra Row R and the only thing I remember being obstructed was the top part of the stage (and I already knew what that looked like because I'd already seen the show from the mezzanine).
I've been about halfway back house right on the aisle and it wasn't bad, but it was my second or third time seeing the show. I think the only parts somewhat obstructed were the "groupies" behind velvet ropes. Being house left might be slightly preferable thinking of staging, entrances and exits.
I sat in E-9 (5th seat from the aisle, about 2/3 down the row) There were no problems. On the furthest to the sides, you won't likely miss much. Most everything is played downstage center. However, you'll miss part of the spectacle of the splashy musical numbers.