I use all four pieces and the power tool, but they are vary heavy (i have to take the boots and legs off to fly faster then i can run and if i hold the power tool with all armor on, i am too heavy to fly or glide) as i have put almost all the modules into them, flight control is nice if you need to do any hovering for constructing, say a bridge across a canyon, or just to take one of the billions of amazing views the world gen comes up with. Though with night vision it is a hard (impossible, almost) to tell the true light/darkness so suggest taking it off when underground so i you know where to put torches at. step assist may bug you a tad when your trying to dig a level tunnel with the power tools.
Ive got everything turned up as far as it will go. The parashoot does not work when the helm equipped because its hover is default for flight mode likewise swim and jump and to an extent sprint also conflict with flight, but its a simple matter to either make a second helm or simply remove it. While it runs on MJ power 25m for the five upgraded batteries, the power is shared between all the units you use, it does drain from itself first but when empty will pull from the others, atleast for me.
We did find a bug or glitch that if you break a MFSU with the power glove, it would feed back and act like a supercharged explosion, with the armor and gloves power of MJ combining with the MFSU's shared EU power and make a massive explosion, it took our our pair MFSU's, trio of generators(basic), our extractor and compressor and a pair of both electrolizers and centrifuges, also the mv and lv transformers. As well as everything that the guy had on him, and our barrels of diamonds, rubies and redstone.
Needless to say we moved the IC2 stuff down a floor and put a double layer of xzy-shields in place above it, and spread out wit no machines near the mfsu's or each other.. the walls are 20x20 and the line follows the wall, stepping down each side from high to mid to low. We also implimented a no touching IC2 machines (to move, not for usage) while wearing the armor. And installed one charging pad. Its quick enough, but i like the idea of a 4 square pad, will have to impliment that once i finish this rail tunnel.