What is it about ACT that you don't like? We've managed close to 5,000-7,000 contacts on average in our ACT database for years and never had a problem with it. Personally, I've been using ACT since it was a DOS program 10 years ago. Tried Goldmine, Maximizer, etc., etc., over the years and none were as efficient or as powerful as ACT.
If you got questions on the software there are also a multitude of books out there on it, the best is probably any by Jeffrey Maher, he's a consultant who trains companies on how to use ACT in their departments like sales, customer service, etc. He's also the one who wrote ACT 2000 for Dummies. Even after using it for many years I picked-up that book and learned a few things that I didn't know.