First Trainer...
I would have to advise AGAINST the Avistar as a first trainer. I learned on the Avistar, but let me tell you a little about it.
First, the airplane has a semi-semtrical wing instead of a flat bottom wing. The flat bottom wings slow way down for landing and can be flown moderatly fast once you get the hang of it.
The way that Hobbico tells you to set the throws on it is way too hot for a beginner, however, it's nice for the instructor to have all that throw. More throw, means you can get into trouble faster. You can dial in any airplane to have more or less throw on the control surfaces, but this one is setup too hot.
The semi-symetrical wing means higher speed take off's and higher speed landings. When you're learning you don't want this kind of speed. You want to take it nice and gentle.
Now to address the issue that always comes up... What about when I want to do tricks with it and fly aerobatics with it?
Good question. Here's my good answer... You don't want to do aerobatics with your trainer. It wasn't meant to do that nor is it that good at performing them. This is what your second airplane is for.
The trainer is for learning the basics of flight, take off and landing. Flat bottom wings will fly inverted and they can be put throught a nice loop or a roll. They just don't do it as pretty as something that isn't a trainer. When you stop to think about it, you don't REALLY want to do aerobatics with a trainer anyway.
Having said that, my Avistar was setup per the instructions as was too hot. When you get something that's too hot it doesn't build your confidence as fast as something you feel more comfortable with. After 7 flights on it, I totalled it out.
Then I bought a flat bottom wing trainer like the Superstar 40 mentioned above and it was so much easier to fly. Since my confidence had been shaken, I needed as much of it as I could get. Stick with the flat bottom wing to learn on. The LT 40 or the Superstar 40 are excellent to learn on.
If you look on the box of the Avistar it says "An ideal second airplane".
Don't get me wrong, the Avistar is an excellent airplane all around, but it's a little much to start with when training.
Just my $.02 worth,
-Snaggs