Probably the CCI AR Tactical for me for plinking at 25-50 yards but they have seemed somewhat limited in availability.
I've had really good luck w/ the Aguila Super Extras and they are relatively cheap and seem to be consistently in stock through MidwayUSA.
Mine had done a very good job of cycling everything I've fed it in ~ 4500 rounds so far (CCI MiniMags; Federal Bulk, AM22, and Champion; Winchester Super X PP in addition to the above) my preference is mainly just around what seems to be more consistent grouping w/ the CCI Tactical and Aguilas.
I think I'd stay w/ my 9mm Hornady Critical Duty for HD but if I was trying to kill/disable something w/ the 15-22 I'm thinking I'd probably go w/ the MiniMags or SuperX out of what I have sitting around.
I think the restriction on Stingers is just for the Performance Center model and is due to the length of the cartridge rather than the velocity, but could be wrong.