.224 Valkyrie is essentially a .223 redesigned to better handle long for caliber bullets. It produces similar velocities for the same weight of bullet as a .223, but .223 cartridges can't really handle 95 grain bullets.
If you're really into long range, precision shooting using the AR-15 platform, this caliber will be a good investment. Unlike most of the other new .22 center fire cartridges, the Valkyrie doesn't come with additional recoil or overall length.
Otherwise? It doesn't really bring much new to the table. It might make a decent military round, but increasing the caliber (to at least 6mm, preferably 6.5) would be a better solution.