My quickest pass in my 15' Hellcat M6 (DA was around 3k-3,500):
My quickest pass in my 19' HC Redeye A8 (DA was 1900)
Now to be fair I had better DA with the Redeye. I think I could have possibly ran an 11.5x-11.6x in the M6 if I could have had the same DA. It was freak DA though. Our track sits at 2,350ft so we rarely see something like 1900 DA. Both cars are stock power, on same MT ET R tire. M6 had the barton shifter, and the Redeye has the factory rear seat delete. Besides DA being perfectly equal this is about the closest comparison I can make, same track. The fastest I've seen a Hellcat A8 run was 11.06, same day I ran my 10.46 in my Redeye. So on it's best day the M6 is around half a second or slower than an A8 Hellcat and over a second slower than a Redeye. I was by far the best M6 driver at the track too (That I have seen so far). Other M6 Hellcats couldn't break out of the 12s, some ran 13s. I took a 2nd place trophy home with my M6 bracket racing against all autos. I took a 1st place trophy in the Redeye.
IMO these cars were built for speed, and the A8 is the superior choice for that. I drive my A8 more, I just enjoy it more than my M6. Not just because manuals are slower in racing, but because I never cared for the bad 1-3 transmission gearing and the notchy shifting. My 05' Neon-SRT4 shifted like butter compared to the Hellcat M6. I loved that manual. The Hellcat manual just doesn't really feel like Dodge put much R&D into it like they did the A8.