If I put a 15 tooth front sprocket on my quad will that give me more top end but take away some low end or should low end stay about the same?

 

The 700 has enough low end torque that you won't feel much of a difference, if any at all.

 

You'll definitly gain top end with that HP and Torque.

 

I guess I should be a little more clear. You won't feel much of a difference with the low end. I don't know how tall the stock gearing is on the 700, but most quads can gain at least a couple mph with a bigger sprocket.