The Cooler Master Mastercase H500M is not simply an updated version of the H500P with addressable RGB fans. Cooler Master has taken the opportunity to tweak the case in almost every area. While this makes it a bit more expensive, the results are like night and day.
Any major computer upgrade generally requires a full software reinstall too. No so if you heed the advice in the guide to Upgrading a Motherboard without Reinstalling. PCSTATS Tips