I've never personally had a problem with the time it takes him to update, only because I kind of know what it is like to have so much work to do. It just becomes stressful if you keep to a deadline or the such, it becomes a lot better to work when you can post your creations when you’re ready. I'm not really as much of a fan of his works these days as when I first discovered the site a few years ago, but I still check when he updates and sometimes find something I like. Regardless though, I think he has every right to take his time.
My only issue with SK is generally how he responds to emails and what not. Whilst he doesn't seem rude or anything in particular, there doesn't seem to be any sense of formality of professionalism with his responses. I sent an email not so recently and the response I received, whilst direct, wasn't as informative as I would have expected. It was nice that he responded, I just would have liked more elaboration upon my answer instead of a plain yes or no. Still, he's had his site running for a while now, so he must be doing something right, and he must be treating the girls right too for them all to stick around with him so long.