I have an A and a C model, as well as a Mini 14 and several AR's.
The A is a decent rifle, although personally I prefer the C model since I like the sights better. My C is slightly more accrurate than the A, probably due to the stiffer barrel, but with 52 gr. Black Hills HP ammo the A model will still shoot 1.25-1.5" groups at 100 yards, it seems a little more finicky than the C regarding bullet weight.
Niether of my SU's have more than a couple of thousand rounds through them so I really can't say about how they will hold up longer term, but so far so good, no problems at all with either one of them.