i think they are similar, i would think the asrock is a tad better with a 3 phrase soc vrm, versus a big 2 in msi board. since you are running the APU, vrm on SoC actually matters, feature wise, they look quite similar.
tbh, i would choose neither and get a board that has a heat sink over the vrm. make sure you have some sort of air flow to help cool the board as both mobo doesn't offer vrm heatsink.