I have a Tower Trainer 60. I love it! It is easy for my 50+ year old eyes to see and it almost flys itself. I even put floats on it for use off the snow and the soft snow this summer.
I'm sure anything that maintains a proper attitude is good. My instructor just taught another fellow on a "Sturdy Birdy" and that seemed to do well too.
I have a pic of my Trainer in my gallery if you want to take a peek.
Good Luck,
AL