Although I prefer the Super Tool to either, if restricted to that choice I would take the PST, or maybe the PST II, if that is an option.
I regard any multi-tool as a sort of emergency or "at hand" devise. The PST/PST II are harder on the hand than the Wave, but can be put up with under the circumstances I would be most likely to use it. If gloves are available, or a folded handkerchief, differences in hand comfort between the two
becomes negligible.
OTOH, the PST weighs only 5 oz. compared to 8 for the Wave and is smaller, can be a true pocket tool. The Wave, IMHO, is just enough larger and heavier to be a belt carry only proposition. Of course, my fave Super Tool is even bigger and heavier, but once you are packing on the belt, the extra weight is not noticeable, so you might as well go for the extras. Same goes for the even bigger and heavier Swisstool.
While the Wave is very useful and attractive,
I prefer the locking tools and robust build of the Super Tool. If rounded handles and convenient access is paramount, the Swisstool is an even better choice. If it had been on the market a few years ago, I might have gone for it, but like the ST well enough to find no need to switch. Suggest you try them all out, if you can.