There's nothing wrong at all with Walmart bikes as long as you adjust the bike yourself. I rode a Walmart bike from SC to TX with the only problem of a few flats and a brake adjustment. Not even a single loose spoke. I've also read a lot of journals at crazyguyonabike where they spent 10 times what I spent and had to constantly find an LBS to tune up or fix their bike.

I currently am riding a Walmart bike, a Schwinn Aluminum. 1,400 miles on it so far and again, only a brake adjustment needed. Not a single problem outside of that.

Walmart bikes work great but don't expect to be welcomed by roadies who spend 20x more on a bike and then spend more on adjustments & tuneups at the LBS than you spent total on the Walmart bike.

And you can't beat the return policy at Walmart.