Thanks Rick for the tip about Photozone.de.
I like DXO.
Their data is very comprehensive and one thing they do is sort of equalize (normalize?) the various data such that you can make broad comparisons between camera makes and models as well as lenses of various manufactures on different cameras.
I find their "Which Lenses are best on ____ (fill in your camera model)" rather interesting. Say you have a d7100, or D600, but it also also allows one to look at a lens on one camera, say D7100 and then look at DXO's data for the same lens on a D600/D610, say if you want to upgrade someday. They also have an overall scoring system plus several sub-categories called Sharpness, Transmission, Distortion, Vignetting and Chromatic Aberration. I find these measurements far more comprehensible than manufactures' MTF charts, which apparently can't be compared from manufactures' charts to another. DXO's system is not perfect but it's a place to start.
I find Ken Rockwell rather interesting, and some of his information is pretty good. But his info has to viewed as just one point of reference. He's definitely very opinionated, and his reviews tend to be somewhat skewed because some of his advice would appear to be coming from a mainstream pro photographer, but if you read his background it's hard to tell what his real background is. Seems he he has technical background in digital imaging and claims to hold several patents.
Jared Polin is a little crazy - sniff testing new gear? Huge Fro. You can glean a few things from him here and there but he's more entertainment in my book. Some time back he dedicated one of his Youtube videos railing on Ken Rockwell because as noted Ken thinks shooting RAW is a waste of time and Jared promotes RAW big time.
FWIW