This game is amazing now this depends on what you are doing.
Role play servers in my opinion is were i spend all my time some game modes are lackluster or missing things and it gets over bearing.

The major servers are icefuse upcoming gaming light the one I choose is nationaltaskforce.net
Usually the servers are always being worked on and improving. this goes for MOST good networks.

Now the biggest issue is either LAG or the staff team chosen by each network

Lag
Now this depends on 2 factors optimization or users online

admins
This can depend mainly one the size of the community the bigger it gets usually the admins get worse.