Interesting question! If your images a grossly over/under exposed and you are having to use exposure compensation for most of your shooting, something may be a-miss? If your exposures are close, then perhaps it's the choice of metering pattern you are using or the focus point used at the time of exposure?
I've always been amazed how well Canon SLR/DSLRs meter! I am sure there are many other photogs out there that have found this to be true as well. However, I don't think people really trust their camera's metering, which has always baffled me. I don't think my experience is unique either. Having owned over two dozen Canon SLR/DSLRs, I fully trust their metering. That doesn't mean they are perfect. However, for the majority of subjects and lighting, they have never let me down. I have shot just about every kind of subject you can imagine over the past 31 years and never had to rely on a handheld meter or had to bracket to get the shot! And that was about 26 years of using film, when you didn't get to "Chimp" (see the results instantly) your shots!
As to what I have experienced with my cameras, I have found that my 5D and 5D Mk II bodies tend to underexpose by about 1/3 - 1/2 of a stop with most lenses. My 7D overexposed by about the same amount? This is not a problem and if necessary, is easily corrected in DPP. Both of my 1D Mk IVs are spot-on. My film bodies (EOS-1V and EOS-1n) both underexpose by less than 1/3 of a stop using slide film. I believe Canon says that an exposure of +/- 1/3 stop is well within specs for their "Pro models" and +/- 1/2 stop for all others.