I have both. I actually prefer the regular sks, but the D does have the "look cool" factor with the big ak mag sticking out of it. I've only shot a few hundred through the D, but no misfires or problems. I think it's just as reliable.
The D is worth more because there are far fewer of them in canada. And as far as we can tell right now, there aren't any more being made. So if you want an sks that takes ak mags, you gotta pay a bit more.
I agree with you that the stripper clips are nice. Especially since most surplus ammo comes preloaded on the strips.