If it would be to no cost to random and it didnt ruin the latency of the server then i think extending the player slots from 16 to 24 would be a great idea for the following reasons:
Over here where i live around this time that im posting TTT gets reallly full and i often have a lot of my friends steam chatting me asking to when the maps gonna change so that they can get in.
(Personaly) dunno wether its my luck or Gmod just hates me but i often find myself in the reserved slot and when one of the admins come in i find myself kicked
I think it would be interesting to see how it will be when there are 4 T's instead of 3 (or possibly moar XD)
Nid more people to kill =]
Just a suggestion i decided to post up in the meantime i wait for a slot to open up =D