I find them to be no more difficult than the voile systme, once i'd worked out a method: work your way from one end of the board to another. So, tip clip, the nearest pull clip, then flip upside down and do the next pull clip, then end on the last tip clip. With a bit of practise (i.e., once) you're good.
I've got them on a 172 Prior BC Split which I use in firm snow conditions. I'm using them with a hardboot setup on plate bindings.
I can notice a difference in really hard snow, I get less "chatter" from the board. Hard to say how much it actually makes me a better rider though. It does feel more solid which I like and I would spend the $50 again for them. It's somewhat of an incremental improvement over hooks and nothing revolutionary but I would recommend them.
On my powder board, I haven't bothered and probably won't.