Even if airflow wouldn't be an issue, i'd still go with Fractal Design since it has a lot better build quality compared to the Cooler Master case.
Here's in-depth video review of H500P for you to look at,
youtube:
https://www.youtube.com/watch?v=HRsb4C5gLLc
After watching this, maybe you'll understand how bad of a case H500P really is, despite it looking good at first glance.