I've had really good luck with Vortex HST/PST scopes.
Currently I have a Strike Eagle 1-6x24 scope that seems to deliver poor performance. The scope looks fine, I cannot identify any kind of mechanical failure or obvious defect. I realize this is a less expensive product but it's still "not quite" right.
I've used the scope on three different rifles, trying to verify that the problem is the scope, and it consistently will not shoot a group comparable to other optics with same/rifle/same mount/same ammo and all things equal. I have meticulously checked mounts and rings, all good.
Its seems like something mechanically in the scope is slightly loose or misaligned and the scope just doesn't perform as it should (but it almost does). For example, shooting a mid-length AR with a Burris 1-4x24 and 77 grain SMKs from a supported position, I can consistently shoot around 1 MOA. Switch to the (quite similar) Strike Eagle and the same ammo, same gun, same mount, same shooting position and it shoots 3-4 MOA. I understand the "thick" reticle on this optic is not intended for shooting tiny groups but it shouldn't make that much difference.
Any thoughts?