Originally Posted by
ChowChow
You'll get more gears options on 10 speed vs a 9 or 8 speed etc. That way when you won't be shifting the front derailleur as much. Plus as the higher the speed, mostly the better the derailleurs are.
10 vs 9 isn't that noticeable if the smallest and largest ring size on the cassettes are identical. I would avoid an 8 speed.