I flew a Kadet Senior about 10 years ago with an OS 40 in it. It was so stable and slow I soloed after one buddy session. I could take off and land the first day I flew it. I highly recommend it for someone who wants a VERY easy trainer. The building was a little involved but perfect for a first kit if your new to building. The fuselage is built up rather then the long complete pieces of balsa in other trainers. This also keeps it very light. It didn't take long though to get kind of boring. With just a 40 in it a loop required a bit of diving first to get enough speed. No "stock" ailerons are the biggest draw back I see. Rolls are next to impossible without them (at least for me) . I flew it 3 channel and had a blast with it.

Stan