Well basically a really good one cost more then your house and most of the cheap ones Ive heard were so so at best.
There are many models in between those price ranges such as the HK Linear Tracker which some members seem to like. I have never heard em so I cant comment on em.
I do have a Maplenoll LT table that I like very much but if I dropped it at your house you would prolly sit there and say "WTF" do I do with this thing. Meaning they are not the easiest to setup and or use.
Grumpy