I second the 4* .40 or .60 the .40 was my 2nd plane . I also started flying the Hanger 9 Twist just a couple weeks later . I love both planes and I got them last sumer which was my 2nd flying season . If you go with the Twist make sure you start on low rates and set the CG so it isn't tail heavy . Do a search on both planes you will see that many flyers went to these 2 planes for their first low wing aerobatic trainer . The 4* is not as aerobatic as the Twist but it is probably the best choice for a 2nd plane after a high wing trainer . It realy depends on how well and confident you can fly a trainer as to what to get next . I can give you no opinion on the CM Pro 330L as I hve never flown one .