your size/frame size is probably the more important question...i know it's only $80 but, if it doesn't fit you it's wasted money that you could have added to the other $320 that you'd need for a brand new, entry-level speicalized (e.g., hardrock).
Mine has shimano components which means that they last longer. They are the best.
And also Carbon Fiber, I'm assuming you know what it is. You have steel alloys, aluminum, titanium and then Carbon fiber. It's very light material it feels like you are flying. All you have to worry about is your own weight.