i disable addons for servers when i can, but only on dedicated ones like if i'm doing a city build, i'll just have default plus events/playertypes/JVS and other useful things, notmany guns, and if it is a TDM one, then it will have just the guns i use
although, i just make a dedi for each one :D
on my normal server i just keep them on so that it's easier to see what i have avalible and it's on when i need it