I have been running my 2016 Ultra with the Baffles out, High flow AC, & a FP3. It is loud, but runs better than stock. Probably no torque gain down low, but way more pull up to about 4500 rpm.
It will be awhile until I can afford a complete system, so this had to be done. No way was I going to ride around with the stock pipe sound.
you cab drill the cat out with a 1" x 16" paddle bit. go slow and use a good drill. most importent is to hang on to it. did this many times and you can get all of ity out, no matter what anyone else is saying. do a search on here, many threads about it.
If you do take the baffles out, consider adding some Thunder Torque Inserts from DK Custom. It's a long story, but I have them on mine, and they did help bring back some of the low-end torque when running without the baffles.