RE: Nexstar to Ultra Stick
The Ultra-Stick 60 was my second glow plane after my Nexstar. I found it easier to land than the Nexstar because of a very predictable sink rate. The Nexstar would float forever. It is a point and shoot airplane, meaning it is not self correcting. When you put it in a bank, it stays there until you take it out of the bank. The Ultra-Stick is a tail dragger, ground handling is slightly different, but the U.S. is an easy handling tail dragger.
If you were smooth with your Nexstar, I don't think the Ultra-Stick will give you any trouble. Just keep it on low rates until you are used to it. I would say go for it. It is a fun plane.