I have had four MKII's in my day. I currently own and shoot Bullseye with two. The 6 7/8" Slab side SS Government Target model is not your average plinker. But with the target grips, is pretty well balanced. I also have a 4 3/8" Bull Barrel SS Target model. It is much better balanced, and still comes with adjustable rear sight. The bargain model is the Standard MKII with 4 3/8" tapered barrel. Still an accurate plinker, it does lack adjustable sights. And to me, they are required. You have to get the Government model to get scope mount options I think. Else, other than the 'new features of the MKIII', they're all equivelant internally. They'll all accept aftermarket triggers, springs and grips. I'll admit though, the Browning Buckmark Camper model has a better trigger out of the box. And it's still available with 5" barrel. It's also extremely well balanced. But if you're a Ruger fan like me, the MKII is a great choice. For functionality and resale value, the Bull Barrel Target Model with adjustable sights is the one to get. And the price difference between Blue or Stainless is neglegable in my book.
If they offered a 22/45 MKII in a polymer bottom, with the adjustable sight, stainless reciever, and 5" Bull barrel, then that'd be the cat's meow.
-Steve