ASRock AB350 Pro4 vs AB350M Pro4. What are the differences?

I saw a single previous post on Tom's, with this specific question. However, Asrock technical support informed me that there is absolutely no difference besides the form factor. He appeared to be reading this information off the website, but did not sound like he had prior knowledge.

Before I purchase, I'd like to know for sure if there is any difference between the two boards or not. Thank you.
 
Performance wise, zero difference. Of course there would be some compromises in the Micro-ATX board, like fewer PCI-E slots, perhaps fewer SATA ports or USB connectors, etc. And of course, the AB350M is smaller.

Coincidentally, the three differences I have mentioned are the exact three differences between the boards - fewer PCI-E slots, fewer SATA ports and fewer USB headers.