My feelings are this, 9 ball/10 ball should only be played on 9 ft and 8 ball should only be played on 7 ft. Whether pros or amateurs. Reason is 9 ball and 10 ball become to easy on the 7 ft table and the same for 8 ball on the 9 ft table.
7' tables are easier for sure. However run outs aren't common because of congestion of balls. So I play and practice on a 7' table because it's available to me but would rather play a 8-9'.