I put a Vortex Crossfire on my 308 and the glass literally rotated loose internally after 20 rounds. I bought it used, so who knows? BUT they have a kickass warranty, so it shouldn't be an issue for me. I just need to make the call.
Put one on a savage 110 in 7mm rem mag. Have had 147 rounds through it so far with no problems. Even used cheap rings since nobody had high enough good ones here.
I have a low mag Viper on a KHornet that I've not knocked around much, but seems fine otherwise. I always wonder about the rest of a lineup when I find something new that isn't awful.