Sorry, mr-r, as far as I know, HippoHands are no longer on the market. They will fit over brush guards, so whatever your throttlemeisters are, the HippoHands will probably fit, no problem. In fact, something like brush guards is necessary to keep the big, flat front from blowing back against the clutch and brake levers at speed. There is plenty of room inside for grip heaters, fatter grips, well insulated and armored gloves, quart of oil, ... . There are also various types of HippoHands for different types of bikes.
HippoHands are designed so hands go in easily, all controls are accessible, though everything is done by feel because nothing is visible, and the hands come out easily in case of a wreck. They are also designed to be lowest at the back so any water that gets in can find a way out without soaking your gloves. However, no water has ever gotten in my HippoHands (it's tried) so I really don't know about the self draining feature.