Got to respectfully disagree on this comment. Never had an issue with the MFC tuner response being slow - not on my rig. If it's slow and laggy, then [IMHO] something is wrong with your setup (or your unit). If you are running 50 feet of CAT5, then maybe.Note that the tuner display of the MFC is very slow and laggy. I ended up never using this feature, as I simply could not get the same accuracy as when tuning with the Axe front panel display. If you can't have your Axe in visibility range on stage, I really recommend getting an external tuner pedal!
You would have to have large feet for the buttons to be inaccessible. I have no problems in that area. Yes, the MFC is not the smallest unit, but it's solid.I also think that the buttons on the MFC are sometimes a little bit inaccessable. The board itself is very high; the switches in the upper rows are difficult to hit (at least with my large shoes, lol). The buttons on the MFC are not really suited for tapping tempo either, as they are not "smooth" enough. I ended up buying an FS-5U for tapping tempo.
I've used a number of controllers over the years (wrote the wiki on how to make ur Roland FC300 work with the Axe) so I'm not new to this stuff. To be fair, there are other controllers out there that will work with the Axe and I've used some. None are essentially plug-n-play. If you don't want the hassle of all the setup time/programming, then the MFC is the way to go.