I do agree with the loading/unloading part. My Single Ten isn't really any slower to load than any other (and I also have a MkIII 22/45). you can actually load two per 'click' on the ST.
I also like the fact that a SA does seem to make you 'slow down' and enjoy the experience more. With the current state of .22 ammo I sure ain't burning up the 22/45! Matter of fact, it's hardly been shot because the craziness started right after I bought it.
I actually have been hunting with some Aguilar shorts in the ST recently. They had two boxes left at SW so I snagged them...
Anyway, this is all opinion and as long as the kid doesn't get a POS ANY .22 handgun is usually a barrel of monkeys level of fun...