Wrel has done some testing along with the theory craft and whatnot, and really, assuming you're not fighting at 40+yrds (long or above) range, soft is always a clear win. At best it cuts one or more bullets off your TTK at multiple ranges, beyond that it adds zero bullets to your TTK.
As for HVA, it almost never is worth it. It doesn't do anything useful to TTKs for any but a small handful of guns in a narrow range band. And there are several guns where HVA gives sub 10 units of velocity increase (which works out to tiny %'s increase when we're talking most guns normal velocities.