I can't imagine not having one. Being able to let go of the wheel to help rig lines and stuff like that is invaluable. I take a lot of people that I have to help out and it really has paid for itself. Not to mention it's much safer to navigate, when you can pay more attention to what may be in your path then trying to stay on your path.
Yep, I love my autopilot and I'd pay twice as much if I had to. Mines a Furuno and I have nothing but good to say about it, but there are a few others that are very good also. It just comes down to what you want. I wouldn't go cheap, a poor quality AP is just a headache and can be dangerous. You don't have to go crazy either, just do some research and get one that fits your needs.