If you want to use the highly optimized PPSSPP emulator to get an MK9 experience, downloading a customized Mortal Kombat: Unchained ISO is your best route. These mods offer several distinct advantages:
Since "Isoroms" is not a prominent site, it's impossible to definitively label it as "better" or "worse." The most important takeaway is this: The quality, safety, and reliability of a ROM source vary wildly. A site that works perfectly for one game might be a source of malware for another. Instead of fixating on a specific, obscure URL, focus on understanding the characteristics of a good source:
Go to the Google Play Store and download (donates to developer) or PPSSPP - Free (identical performance, just has a small ad banner).
The search for a is incredibly popular among fighting game fans. Players frequently search terms like "isoroms better" looking for high-quality, compressed ROM files to emulate this iconic fighting game on their mobile devices.