Yep. I have never seen a built in meter in any digital camera that gave accurate exposures for the types of things I photograph. Every single photo I make with my 5DmkII is metered with an incident meter, and the exposures are consistently perfect. The built-in meter's display always says I am off by a stop or more, and it is always wrong.
Even if it were calibrated correctly, its still a reflected-light meter, with all the limitations and issues that brings.
I am not a photojournalist or sports photographer who has to work fast to get fleeting action; for them an imperfect exposure is not a big deal. For me, it ruins the shot. I have time to work with my subjects, so there's no excuse aside from laziness to not make sure the photo is perfect.