Ratshooter - I have one of the Tactic TTX850 transmitters and it seems to be a good deal. Only complaint is I seem to have fried a diode in it and so cannot use the wall charger. The SLT technology appears good in use and the price is right. It's an improvement over the Tactic Module I had been using on my Spectrum and Futaba transmitters to handle the SLT models I have.
The 610 is very much like the transmitters I was using in the late 70's. You will outgrow it FAST. But, with no model memory it will teach you how to properly set up linkages if you want to use a second model. You'll have to bind to it to each model every time you use it. That will be a pain.