Ive got a very similar but slightly different model. Its a 4-16x44 viper HS LR I think is what they called it. Its not the best glass but has served me fine. 16 power leaves some clarity to be desired. So far I haven't had any issues with it tracking holding zero or returning to zero. I did send it in have them check into it. It didn't have enough adjustment to zero on my rifle and it was the 2nd rifle it had the same issue on. They said their was nothing wrong with it, but after disassembling and reassembling and sending it back it doesn't have the same issue so they corrected something.
I bought mine with some really good sales/discounts from cabelas about 7-8 years ago for just under $300. I have been happy with it for what it is, but not sure I would buy it again.