I'm 50/50 with Vortex right now.
Bought 1 SPARC II, no issues. Sold it a while back as I upgraded to a SPARC AR.
Second SPARC II, had issues, sent it back, they replaced it with a new one. Great. Sold it a while after.
No issues with the SPARC AR at the moment, but only a few hundred rounds with it mounted.
Bought a PST 4-16x50 FFP scope based on my experience with the SPARC II. About 500 rounds through it and the rifle its on, and now the illumination is flickering. Swapped battery, problem still exists. Guess this will be going back tomorrow too.
This last one is really frustrating. No doubt they'll fix it or replace it, but I will miss a low light shoot, not to mention removing it from the mount, removing the bubble level, and 'waste' all the ammo/time/range fees etc. I used getting everything sighted in and trued.
Again, I'm sure they'll take care of it, but 2 for 4 isn't a good track record for me. Will probably look elsewhere on my next purchase, and I was super close to picking up a Viper spotting scope.