Paula, most of the .40 trainer planes are 6, one half dozen or the other. They all serve the purpose well and (the flat bottom wing ones) all have roughly the same flight characteristics.

The Tower trainer is also monocote covered (good) and probably came from the same factory that makes the Superstar and Avistars. Even though all the .40 engines included with the RTF will fly the trainer just fine, the Tower .46 does lend itself better to migrating to your next .40 sport plane. I wouldn't let that be the sole determinant for your purchase though. You might find later that what you want for your next plane is nowhere close to a .46.

I agree the Avistar is a trainer.

Personally, I don't like the Alpha trainer's 3-blade prop. I've seen several of these come to the field lately. One prop strike, and you're back to a 10x6 2-blade prop.