Depends on your parameters. MOSFET amplifiers are fast, occupies less area and consumes less power compared to BJT's. But the gain of a mosfet is very small. The intrinsic gain of a single mos transistor is very small compared to that of a bjt. Also, while scaling down, you'll need to work with lower and lower supply voltages. In that case, MOS performs better than bjt as the supply voltage is decreased.
So, if you want speed, less area and power saving, then mos is better.
It's main Disadvantage is : "It is more costlier then Amplifier."