OK, help me out here, please - what does the B550 give me for the £50+ extra, for the intended build that the B450 doesn't? I'm aware of the M2 from PCIe 3.0 to PCIe 4.0 but, to be honest, an M2 PCIe 3.0 is more than quick enough, realistically and I'm not going to be getting 4000 MHz RAM and...