Love both cameras. I had the 7D first and thought it was everything I wanted, but I decided to get the 5D Mark III to have better low light IQ and wide angle perspective on my wide angle lenses. I craved the look of the 50mm 1.2L on full frame. I hardly ever use the 7D anymore. It mostly gets used by my friends who borrow it. The AF system of the 7D is great and snappy as you mentioned, but on the 5D Mark III it's even better (by a significant margin). The 5D Mark III takes the best of the 7D, improves upon it, and adds a full frame sensor. The only thing missing is 8 fps, but I don't do a lot of burst shooting, and 6 fps isn't bad either.