There's two sides to that argument.
Firstly, the blade removes less wood than the thicker blade, which makes it easier to push wood through your saw.
The flip side is that if you are cutting difficult wood, the blade will tend to heat up more, which in turn causes the edge of the blade to expand slightly. This is what gives the blade that characteristic wobble.
I find that if you make sure the blade is kept sharp and you don't push it too hard, that the blade will stay flat and do an excellent job. Don't be tempted to run the blade once you notice that it is starting to dull and you should be fine.
OK, fess up...which one of you clowns stole my sig? It was right here a second ago.