I just got the Morgan Carbtune a few weeks ago. Recieved it from the Morgan in 7 days, not bad IMO. No regrets, should have gotten it long ago. I himhawed around with the idea of making my own (thats how I usually do things), but wasn't sure it would be as accurate as the Morgan. I can't speak for the others but the Carbtune works and I feel it was worth the price.