Collaborative filtering dataset preference?

Hello,
For collaborative filtering, is it better to have less users with more reviews or more users with less reviews or does it not matter?

For instance:
is 200 users with total 20,000 reviews
or
2000 users with total 20,000 reviews
better?

The more review per nb_user*nb_item the better (as it means that you have more information on your users).

If you have a lot of user but they only produced one review each then you know very little about them.