The question is, do you want the STS or the ATS? I had the HD before and I didn't see any difference between it and the non-HD glass. I've had both of the STS and ATS and I like the ATS better. At first lite, and looking towards the sunrise, the ATS will make you thankful that you had purchased it. The STS is easier to spot game right off, but!!! Good luck in your purchase, you won't regret it.