One thing that has me puzzled and I need some suggestions or ideas for a solution, is that both our TTT servers are identical really. Theres not a whole lot different I believe. Now I do not think going vanilla on one server is a good idea, but I think having different servers is the solution to getting people to play on both servers.
Some ideas that I've been talked to about when I've had discussions about this is having different map lists, or using haste mode, or even going with an entire different weapon set.
Honestly, I dunno if any of these would be a solution or not, so give feedback here.