I have had it done twice. Most recently was about 18months ago and scored a 2.0. I think that had been down from my previous one (2.6 or something?).

The first doc was a cardiologist that I saw because of a special "heart risk" promo offered through his clinic. Everything looked good except that test which he said was an indicator that something was causing inflammation somewhere in my body. The 2.0 was done right after I lost 40lbs with HCG. Even though it is in the "normal" range, my current doc would like to see levels closer to 1.0 or below.
To answer your question, I think it is a pretty reliable test - just not sure how much info you actually get from it.