I'm planning on pulling the trigger on a diamond ball polisher. Should I purchase the 8 or 16? I'm thinking the 8 to save cost and storage space. In my view, taking the extra time to run the second half isn't a big deal for a home table (would be different if it was in a pool hall). How about design robustness? Any notable difference between the 8 and 16? Off hand, I'm thinking the simpler 8 ball with less parts also is the more robust design. Thanks!