Absolutely! Great bike. For 3-6 miles I know some who commute on long boards (skateboards) that far. I think you did well. If you have no intention of taking the bike off road, may I suggest down the road replacing the knobbies tires for some skinnier, smoother, higher psi road tires like the Specialized Armadillos or something of like. Also I think you should be able to turn the knobs on top of your front shocks to the right which will make them as stiff as possible. This will assist in minimizing your loss of transfer energy (poor description). If you stick with commuting and really enjoy it, you could switch out the shock someday for a cheap rigid fork.

Don't get discouraged by the many nice commuter specific builds and purchases you see posted here. I rode from the age of 13 - 28 on mountain bikes with a backpack all over Phoenix, logging thousands of miles a year. Never new anything different until the internet and bike forums.

Good luck, get a good lock, and be safe!

Jeffrey