We all use the same filter. The standard OEM Mopar filter flows at ~750ish CFM, supposedly, right on par with all the top oiled cotton gauze brands. Someone on the SRT forums with a Challenger did the math and figured out the Hellcat filter's true numbers. And on that, I've seen 2 sets of flow numbers: ~1000cfm and 1400~ cfm. YouTube it. There's tons of info there. I did compare my stock 392 filter side by side with the MAHLE LX3482 and the Hellcat filter has way more pleats. So with that being said, it's been a very popular, and cheap upgrade to the 3.6, 5.7 and 6.4 guys.
I can tell you that I first installed an AFE 5 layered cotton gauze for my 392 and I then put in the Mahle LX3482 and I swear the Mahle filter just makes it feel so much lighter on its feet. It's hard to explain. I put in the AFE filter for 1 day and felt like I lost throttle response and took it right back out.
Stevie,
I doubt there's any difference in efficiency. Their material looks different than most other nanofiber filters.