I built one that the grandson is learning to fly on. It has a Saito 30 and weights 4lb 5 oz. The Saito powers it well and keeps the speed slow enough for better reaction time and is very quiet making little more noise than some electrics. A friend had one with an OS .32 and it flew twice as fast. The only changes I made were the addition of round pieces of 1/8 lite ply about the size of quarters at the wing dowels and after some flying the screw axles were changed for some better quality screws.

A great plus of the LT-25 is the ease of repairs as it is all balsa and having the full size plans makes it so easy to repair. In fact, I saved the punch out sheets as parts can be marked from them easier than tracing off the plan.