I think MSI is the fourth largest seller of motherboards currently? Either way, since they are not quite in the "top-tier" you will hear many people say bad things about them. Some of it is justified, like how their VRMs on certain chipsets (970, for example) can get really hot, and when people start overclocking and otherwise using them not according to specifications, bad things happen.
Anyway, the A88X-Gaming is a pretty good motherboard. It's roughly equal to its peers, and probably only something like the top-tier ASUS boards are going to be noticeably better for an enthusiast - otherwise, you'll be hard-pressed to find a better motherboard for the FM2+ platform.