I have Bushnells for many years and have been very satisfied-no problems. I purchased a Vortex Diamondback 4-12x40 about 2 years ago and think it is a great scope. Very clear and sharp image. Holds consistently, never need to re-adjust. I have the Dead Hold reticle and think its one of the best designs. The Vortex lifetime warranty is hard to beat. No questions asked, regardless how you came to own the scope/ their product, no warranty papers to fill out.
I recently stumbled upon an interesting youtube video where 2 models of Vortex scopes are put through a 3 part torture test. Step 1, scopes are completely immersed in water for 24 hours. Step 2, scopes are then placed in a freezer for 24 hours. Step 3, scopes are mounted on a 300 mag rifle centered and test fired and re-checked to ensure the hold their calibration and function flawlessly. Very impressive in my mind.
check it out, just search youtube with this subject line: Vortex Optics Independent Riflescope Test - Part 1 (there are 2 parts of this video)
Sorry I could not provide the direct link.
Fortuna