I have SI, SII and SII Big Sky scopes and all are very good scopes when compared with other scopes at similar prices. My only beef with Sightron is that they no longer offer low power scopes but then there are darn few of them available anyway.
I returned a used scope to them for repair about 2 years ago. When I told them I was not the original purchaser they responded the same way Leupold did in the same situation. They said something to the effect that they warrant scopes, not purchasers and the sooner I sent it to them the sooner they'd fix it and get it back to me.
FWIW, add Burris to the outfits with a "no BS" warranty. A while back I let a rifle fall out of the rack in my truck while banging around in rough terrain. By the time I spotted it the occular bell was stripped and wobbly. When I called Burris and explained the situation they said to send it so they could fix, repair and return it quickly so I asked if they needed my credit card info then or after the repair. They said the same things that Sightron and Burris had, "We warrant scopes...."
Lance