I sent back my USO SR4c because the red dot on the optic was jumping around during various training/classwork situations. I got it back a few days ago, roughly a two or so month turn around time which is not too bad for large company like USO. As you can see from the photo below the red dot is in the right spot.
I had it in a Bobro 30mm mount that I swapped a Trijicon AccuPower over into. I am going to place an order for a Samson 30mm DMR mount for it and see how it works out on various rifles. If its anything like it's older brother, the USO SR8c, I doubt I'll have any more issues.