Aaron is completely retired. Bob Burd is pretty much retired but still regularly logs in. I assist with troll and spam clean-up and a few other matters as needed but am mostly retired and am retired from site decisionmaking.
Josh and Ryle are not actively engaged in SP matters. Montana Matt has made most of the site upgrades the past few years.
I think, as much as I know, which might be very little. I think they all are great. I'm sure the amount of time that must be put in is substantial and for what? A lot of ridicule and B.S. As far as some of their politics go, well that's a different subject (and I scratch my head) but that really has nothing to do with their abilities to moderate, legistlate and proliferate this site. KUDOS!!