I had both and the LT25 is more frisky flyer than the LT40. BOth make good trainers as they are capable of very slow flight and landings. Building tips: when you join the wings together, make the wing joint so that you have 2" of dihedral. Its a lot less than the manual suggests. The plane will still have self righting abilities and will handle windy conditions much better. Second tip, pick up some standard axles instead of using the bolts for the wheels. The bolts tend to loosen off and cause one of the whels to bind. I also went with a 1" tail wheel instead of 3/4" but I don't know if it really makes much difference. I also went with 3" Sullivan Sky Lite wheels for our grass field. Handles much better on the ground. I did modify the wings for 10-32 nylon bolt mounting but you don't need to do this. I just learned to hate rubber band mounting after flying an LT40 for 2 seasons. [>:] Other than that the plane is a nice flyer and will do a decent knife edge.