I don't like them on sporting weight rifles. I'm not fond of them on varmint rifles. Reasons? Disproportional to the rifle, unnecessarily heavy, unnecessarily bulky and in the way, and I don't get a good cheek weld when I have to use high or extra high rings.
On a tactical rifle with a high comb or adjustable comb so I still get good cheek weld they can be ok.
I haven't spent any time shooting one, but in concept the Leupold VX-L may be the best of both worlds. If you truly need a large objective (few of us do during legal hunting hours in the US) and want a comparatively low mount, they are worth a hard look.
Tom
