Prefer cerakote by far, but I did fart around with duracoat years ago and did a Glock slide and a Mossberg shotgun. The park job on the shotgun was pretty deep and the I just degreased the parts well.
The slide held up better than I thought. Didn't chip, it sorta burnished like I waned but didn't expect. It did wear fast in places where parts meet but since I didn't damage the tennifer it doesn't matter and looks good on the outside.
The shotgun, well, what can I say, it's black now and the duracoat seemed to settle in the park job and formed a solid surface. It's wearing well and no complaints.
Then did an FAL. Total fuckjob. Chipped, looked like shit, didn't layer well, you name it. I followed all instructions, did nothing different really except I did prep it better. That rifle got cerakoted and I couldn't be happier.
My foray into duracoat was sorta interesting, on one hand I got phenomenal results and on the other I couldn't get the shit to work. Given Cerakote requires about the same prep, I'd say just go with the Cerakote. I sold all my duracoat stuff and the airbrush and compressor and just resigned to having Cerakote jobs done professionally until I can get the sandblasting cabinet and other gear to do it right. It's not like I need it done often anyway.
As far as clear coats go, didn't need one. Won't need one with Cerakote either.