Any reason NOT to move from 7D to 5D Mark III

I am strictly an amateur photographer. A fun hobby but not my job. I have a 7D + EF-S 10-22mm and EF 24-105mm. Have always shot canon and am considering getting an EOS-5D Mark III. In fact I am really tempted! I know the ES-S lens won't work but I would either keep the 7D as a backup or sell it with the 10-22. If I get the Mark III I would likely get the EF 16-35 or 17-40 as well. Aside from the obvious additional expense is there any other reason NOT to get the Mark III. I guess what I am asking is whether there is anything the 7D does better that I would miss?