Wirelessly posted (iPhone: Mozilla/5.0 (iPhone; U; CPU iPhone OS 2_2 like Mac OS X; en-us) AppleWebKit/525.18.1 (KHTML, like Gecko) Version/3.1.1 Mobile/5G77 Safari/525.20)
They both have laptop sleeves. Having had both, I say this: The laptop messenger is bigger. Almost twice as big. You can't get much more into the commute but some cables and a few notebooks. The commute has many more pockets (inside and out) which can be convenient, as well as a padded back and bottom. I prefer the messenger for the extra space and the styling. The padding in both is good so no worries there.
My standard recomendation is this: I upgrade all the time, and have more than one laptop. After constantly switching bags for different sized computers, I settled on a regular (non-laptop) messenger and various sleeves for each notebook. It adds versatility.