Here http://www.sheldonbrown.com/
I have used the CLBs extensively, both the SpaceLine as well as the Compact Pro. The SpaceLine is the newer, "improved" model. It was advertised as material from elsewhere or some such slogan. This led many to believe it was not alloy. The Ti look to the first, and more common models, also reinforced this belief. However, they were alloy with a surface finish. There was an "aero" plastic shroud over the center bolt. Later (last) models were white and they were eye candy in my mind. The Compact Pros were very similar in performance so long as we are comparing brakes of the same reach as the SpaceLines. Compact Pros came in 2 different reaches. CLB brakes were quite good if one changed out the levers as well as the cables. I found their levers very uncomfortable, especially by today's standards. For me they were fine binders with the DiaCompe aero levers on my Vitus.
As far as the Weinmann 500 is concerned, again with good mechanical advantage levers, they are wonderful brakes and extremely light stock. I think a lot of thought went into Peter Weigle's TT bike and they used the 500. I recently had a Nishiki Cresta tourer set up with Continental Goliath 700x47s and had albeit tight clearance for Weinmann 500s with Aztec pads for the front brake activated by Shimano MTB lever and the stopping power was awesome.
BTW, if CLB Compact Pros are of interest, I have an extra pair, but wouldn't know what they are worth.
Ken Wehrenberg, Hermann, MO