yes, tianci, while that might be true, would you give your F90 (if you still had it) to one of those beginners to fly? i'd be very hesitant. i have the F40 and it does fly like it should be very easy and it is if you have all the settings on mild with minimal throw. but truth be told, it's not as stable or forgiving as a low wing trainer like the WM supersports. plus, it really isn't built to take rough landings, big bounces or some of the very normal beginner abuse. and, it's a terror on windy days due to it's fat wing and light wing loading. but clearly, it is not as challenging as the other two warning suggested.

if you do settle on the F90, i'd say make sure you can fly the plane from take off to landing rather than sometimes letting the plane fly itself (trainers are self-righting). maybe a good test is to fly your trainer inverted a few circuits two mistakes high to see if you can really fly the plane. if you can fly it around smoothly inverted, you should be okay for the F90. second, see if you can land your trainer without bouncing "too" much. try to just set it down nicely. no prop-busting landings. lastly, on windy days, i'd recommend that you bring in the plane with some speed until you're use to the slow flying characteristics of the plane. you could easily stall the plane if you're not careful.

personally, i'd vote for the supersports 40 or the kyosho low-wing calmato. the WM T-34 is also a good choice. but then that's like the hundredth time i've said that since this is the hundredth time this thread has been started