They are both the same graphics chip, just different manufacturers/designs. The difference is so minimal that it ultimately depends on the binning of the chips, which you cannot influence anyway. Another factor is the cooling in general in your system. One person's KFA2 may be faster, another person's MSI. Buy what you like better in my opinion.

If you use the "Compare" function, you will see that the MSI is better equipped, comes with one year more warranty (3 instead of 2) and costs CHF 10 less in the current promotion. The performance on paper is the same.