I have an F30... my two previous cars were a 2006 Accord sedan and E92 M3.
The F30 is very similar size to the 7th gen Accord. Interior seems almost the same to me. The F30 is about 9inches shorter overall length, but I think it's just due to shorter overhangs.
The F10 is bigger all around, and feels that way when driving it. And the rear seat room does not feel substantially bigger than the F30, IMO.