Is Hotwire reliable? DC area, should I book it?

I tend to stay on the Virginia side in the Crystal City area. There are several major hotels there and deals can be had. My preference is Marriott Crystal City, which can be had for $99 or less on given nites. The location is right above the Metro station. Crystal City is the first Metro stop from Reagan National, if flying through there. Both the Yellow & Blue Metro trains run through Crystal City and they circle all the DC tourist locations that you would want to see without any transfer issues.