If my memory serves correct, the Ground Control Pro can be powered via 7 pin midi or maybe a special cable? I'm sure through a search on the forum you can find out.
I bought the mission SP1-LF with the spring load. LF stands for Liquid Foot which is the controller I use. It was like night and day from the EV-5 to the Mission. Not sure about the Boss pedal though. Looks like a lot of people here use that so I may have to replace the EV-5 with that. Edit: I use the mission mostly as a wah and sometimes a whammy. The EV-5 I've used for Volume and Whammy too. You can use it as whatever you want. With the switch option you can switch between or engage a boost or whatever.
Phostenix, I really do wonder why it had such a delay. Its hard to explain but you know the dot which shows the current position of the pedal? You would move your foot and then see it a few milliseconds later or something. The dot almost disappears with the mission pedal because it is responding so fast.