Flyin' fast, I am a relative newbie to the sport (about 2 years now) but will tell you that your second plane is a big step. I am assuming that you have or had a trainer. IMHO, the 4*.40 is NOT a good second plane. Try to get a mid wing plane like a mid star .40 or even a Sig somthin extra. The low wing planes are very touchy and you have to be ready or they will roll right into the ground. After my father flew and crashed his, the guys at our field were saying that the 4* really is harder to fly than people say.
The Super Stunt 40 is a great plane, just be gentle. Any of the stick planes are great. Be ready and have a good time!

My .02