I've used BGs. If your child is a heavy wetter at night though you may want to add in a hemp stuffin as well to the regular insert. The hemp is best because it's thing and absorbent. I need to buy more of them, right now my 6 month old is shoved into a BG with 2 regular inserts and he looks mighty funny. :P
I am new to cloth diapering and just found a great night time combo...I use a Bum Genius 3.0 with a Knickernappies SuperDo! It is a great combination for night time and sometimes my 3 month old wakes up dry after 9 hours of sleep!
There is absolutely no reason you can not cloth diaper over night. Keep in mind though that cloth diapers don't have all the nasty chemicals that disposables do so you may have to tweak your cloth diapering to find a great night time solution.
I've found fitteds and covers to be out supreme night time solution for our almost 15 month old daughter. I really like sustainablybabyish multi snap-less fitteds for her with either PUL cover, double layer fleece soaker, or wool longies. AppleCheeks cover w/ AppleCheeks insert boy folded works well for our 3 year old son that wears cloth only at night.