Anybody like me that has been around archery for over 30 years knows that dual cam is a better concept than single cam. You'll most likely hear otherwise, but then how many of those guys can say they have shot bows with round wheels, steel cables and dacron strings, 20% letoff, laminated limbs. And then made the transition to machined risers, solid glass limbs, single cam. 88% letoff. Well, I have, and this year, after shooting single cams for 7 years I found my way back to dual cam again. It has many advantages. Usually faster, easier to draw, level nock travel, and the string doesn't angle across the bow going from cam to cam.
Single cam is a good concept. Don't get me wrong, but there are issues such as cam-lean that manufacturers need to address. Some bows much worse than others. One place to read about this is at Spot-hogg's website under the letter section.
The issue that some will make about dual cams is that the cables can stretchunequally on the bow, throwing the cam out of sinc with each other. This can and does happen. But with today's modern string materials the stretch is pretty much gone after a couple hundred shots. Then all you have to do is, if anything has changed, adjust it back to origianl and just enjoy the shooting.

If you want to shoot a fairly smooth dual cam system then try a Martin Cougar Magnum with the Nitrous cam. See what kind of speed you get at a certain weight and drawlength. Then go shoot a single cam bow with the same speed and see the difference. I can almost guarantee you that the single cam will draw harder.