I have one of the Agents (alloy frame DS), one of the later guns with a shrouded ejector rod. IT is rated as being able to handle +p, but not recommended as a steady diet.
The DA pull is not particulary light, nor particularly smooth, but I can easily live with it, considering what the gun is for. The rear sight opening is wide (looks to me big enough to drive a truck through), but that can be an advantage sometimes. I have fired a few cylinders full (standard velocity ammo), its accurate enough in my hands, even without extensive practice.
Ten years from now, you won't be able to get that work done
This is a problem with all the Colt revolvers. In ten years, I do believe you will still be able to get any needed work done, BUT, it won't be easy. OR cheap. Or quick. But I'm sure somebody in the country will still be able to do the work and do it first class. Might be only ONE somebody, though....
Get and keep that DS. Shoot it once in a while, all will be fine. Let it sit for a decade, and as long as it isn't rusted solid, it will work when you need it to (recommend if you ARE going to do that, that you remove any lube before storage, as dried out lube is the one thing that will gum it up)
Never was much of a fan of snub noses, but I do like my Agent, and have full confidence in it. I won't be shooting it enough to wear it out, I have lots of other guns to do that with. But when I need something to drop in my pocket (or inside holster) that little Agent is a really nice thing to have.