Out of the 4 I have been able to get my hands on in local stores. The 15x50 is by far the best.... vulture hd 15x56 is second best BUT not close second.
The only other one I've found in my price range that even came close is a Basspro shops brand. Oculpus I think is the brand name and under $300.
It was every bit as clear as the vulture hd.
These days the quality of optics is improving so fast that a far greater effort must be put into seeing the real differences. Set up a test sheet and actually look at the glasses side by side and you may be surprised how different things are under identical conditions.
The optics guy at the local Bass Pro a week or so ago tried to tell me their brand was being made BY Vortex... I am perfectly willing to accept them being made by the same manufacturer in the same plant, etc, but I doubt Vortex is actually making them...
