I was reading the above posts this morning while hanging around a swim meet earlier. I think if you understand the limitations of HSS and work around them it's a nice feature....especially when used for fill.
In light of the (mini)discussion above I asked my wife to stop outside for a quick test shot using a6500 + TT350s in HSS mode.
Manual flash mode full 1/1 power, f2, 1/3200. Flash was off camera left, held by my son ~4-5ft away. I bumped overall exposure only 0.2. Previous experiences with HSS have left me underwhelmed given the massive power loss with the higher SS's. Maybe I should rethink as I actually think HSS works reasonably well in this case despite such a high SS.
Of course the shot looks much crisper on Flickr at full resolution. Can't wait for the change to max size here on POTN.