I like it during peak times when you are guaranteed 20+ players as most of them know their stuff and you end up having great games.
For example, today there i was on marines and the comm (evo.sBig i think), was as organised as he always is. And this time everyone on the team listened and followed his exact orders. Was an excellant game with alot of precision. Ended up winning.
But the negative sides of that is during non-peak times where i would usually expect about 6-8 people playing atleast, mostly non-top 100/non-members. I would be guaranteed a good game and some good kills.
(only reason im in top 100 now atm lol, i play mostly in unsociable hours)
So we're talking about 3-4 hours of actual real gaming from what i've seen so far as a result of this new members only sign. (this is judged from only after a day of seeing it in action and its effect)
So far the benefits outweigh the negatives. But i miss playing against atleast 1 person at four o'clock in the morning