Without addressing the specific cranksets you asked about... Higher-end cranksets tend to be lighter and may flex less. If you don't need to replace yours for a mechanical reason such as being bent or worn, or you want a different length or configuration, then it's probably not your best bang-for-the-buck upgrade.

Also, the crankset interfaces with a lot of other moving parts. They all need to be compatible types and sized to work with one another: bottom bracket, chain, derailleurs (front AND rear), and so forth. If you want to swap a crankset, you've got to keep these other parts in mind or else you may find yourself replacing some of them as well to accommodate the crankset swap.