I have two PST and one HST. All get the job done. Glass is not the best, but very good in the price range. I did a tall target test on the HST a few days ago. It tracked perfectly vertical and had a total dialing error of .3% across 21 MOA of vertical. That is like 1/16" of error at 21 MOA. It is basically error free. I then used the HST at 700 and 800 yards (only 17 MOA needed) and it dialed perfectly and returned to zero. The two PSTs work just as well. One is on a 300 RUM and the other on a 300 WSM with lots of rounds down range on both of them. The the PST glass is better than the Viper HST glass. I find the HST glass a bit irritating, but it works great at 800 yards, so I am happy for the price. Never had to use the warranty and one of the scopes is 7 years old. They've all seen quite a few rounds as I like to shoot some year round. they are not a Nightforce or S&B for for their price point, they are very good.