I went today to look round a nursery for a full time place Monday to Friday, starting February. The nursery looked great, purpose built, good shared and separate areas for all ages, but in the baby room where my son would start there was one other baby and a toddler. Apparently others are attending and some were there but asleep in a separate room.
I can see this two ways - either it's good because my son will get more one to one attention, or it's not so good because he won't be with more than a couple of other babies, for interest/games/etc.
Would this put you off? The older children's room I saw were also quiet, a few children in each, but the preschool room has about a dozen children in who looked to be having fun.
Ds will be 8 months when he starts. I'm going to see another couple of nurseries tomorrow, and I know a local childminder who my older two went to. Just for a bit of background! 
Interested in opinions, I've no experience of using a nursery.