This is what I am wondering. Are the mobile CPUs better at overclocking? Mobile CPUs uses less energy than desktop, right? In that case they must be using lower voltages, which should allow more overclocking, as you can add more voltage without hurting it. Is this true?
No, they are worse at overclocking. Desktop CPUs are better at OCing since the heat can be easily dissipated by the heatsink and roomy chassis. The same can't be said for a cramped laptop.
It'd be inpractical to make a custom case just for an overclock to the speed of a desktop cpu. So then, you should keep it in the laptop case. But then, it can't OC because it's already at the max safe temperature. So if you still want to OC, you'll have to take it out and run it on your desk. Which is completely unpractical, since you can get a nice desktop for much less.