I think FMS is just fine for basic training or fixed gear or belly landing or just learning to be smooth and steady with the controls. Sure it doesn't allow for retracts or flaps, but I can tell you that on first flight with one of my new birds i flew in winds that were stronger than anticipated and crashed. I wondered if my lack of maintaining control in high winds was to blame so I duplicated those conditions (windspeed, direction) with an FMS model of that airplane and go the same results as in real life. So i practiced with different settings to test the limits of the plane and well, when I flew my repair flight, no problems. I say FMS is good to go for free or otherwise. Plus you can find tons of models out there.