I have paddled both. I am 5'10" 180 lbs. The BRAAPP is Narrower so a bit faster and it carries it's speed through turns better. I really like it for "slaloming around" because every eddy you catch feels like it is accelerating you forward. You can pivot turn it but to really squirt it I need a good eddy line and good technique. It is fun to splat and surfs well. It is the perfect Slaughterhouse, Numbers boat. I have paddled it on Gore a couple times. For me it is fine but for example the meat line at gore feels a bit less controlled, (the professor and the double boof felt the same). I mainly paddled in on shoshone.
The Mullet I have only paddled the prototype that was around last summer and only at the Glenwood wave and Salida park. It felt more stable. The day I tried it in Glenwood all the other people preferred it for the stability. It is way easier to squirt and splat. It was also great to catch the wave from the eddy in Glenwood at 18,000. All you could do once you got there was front surf but you could do it all day. The Rocker break is noticeably more distinct which makes me think that the stern would not be prone to grabbing like the BRAAP. That is the big difference with the RPM is that you don't get back endered driving through stuff. At the time, I preferred the more precise feel of the Narrower BRAAPP. The MULLET is fast but squatted through turns. Now I think I am ready to have a bit of an easier time squirting. Who knows.
Anyway, not extensive experience with the Mullet but the two boats feel different.
friend of the fork, knife, and spoon