I can understand the let down, but I agree with ckcollins. The practice at a fraction of the cost is the best part. Fundamentals are fundamentals no matter what you are shooting.
This is what I have and it is a great setup. When money is tight I can still shoot all day with the 22 and when I want to feel the power of 556 I just swap uppers and try to forget about how much it's costing to fire the damn thing. I bought the upper for almost the same price as a complete ar22 but the upper paired with my lower looks like the real thing and doesn't feel like a toy gun in my hands.i guess i could see having a .22 upper to be able to slap on my lower for some range practice...but i dont foresee me ever having a .22 dedicated AR
Sorry to hear that but I give a BIG thumbs up to the S&W MP 15-22