So what do I think? First, the kits: I like the Attack MiG-21; it's quite refined even in 1/144th scale, though a touch fiddly - the wings and horizontal stabilizers have TINY joining areas, and long-term durability is doubtful. The Academy Su-22 is much more crude, simplified and chunky and sporting heavy panel lines that bring the old Matchbox kits to mind. But they're cheap and easy to build, and don't take up much space on the shelf.
The paint: I've been using craft paints for years, and honestly, Vallejo acrylics strike me as being little more than good quality craft paints. They're good, and I'll probably keep using them, but if you have any experience with craft paint, you'll find Vallejo paints pretty familiar. I like the squeeze bottles, and I think they lay down a little thinner than craft paint, but in most other respects, they're about the same. The main advantages of them is that you don't have to mix colors - if you want US Army khaki, you can get it pre-mixed and you don't have to fiddle around trying to mix it on your own. So, I regard them as good and worth using, but not quite the life-exchanging experience that the buzz seems to argue for.
(There is, upon reflection, one major advantage of Vallejo paints over craft paints. I've never found a metallic craft paint that was worth anything, but the Vallejo "oily steel" metallic paint is very, very good. Even if I decide not to keep buying Vallejo paints, that's one that I WILL keep using.)