The primary difference between the two are the Pro series uses MLC NAND which has a higher endurance rating than TLC based EVO series and it is also slightly quicker when compared to drives of the same capacity.
Whether you need this higher endurance depends on your usage model, but for Windows and apps then it's a fair assumption you don't. Also it would be impossible outside of benchmarks to tell the speed difference.
I don't really understand why you are comparing two difference capacities, but if it's because of price you'll be much better off with the 250GB EVO.