2 catastophic DP episodes 1.5 hrs in length, 3 years apart. Plenty of anxiety panic, on the border of DP in between. But the real deal only twice thank god. That's enough for me thank you very much.
Personally cannot comprehend 24/7 DP. I mean, I obsessed about it constantly, felt "special" and alien, like my mind now worked fundamentally differently, and tried to communicate to others about this on a nearly everyday basis. Tried to UNDERSTAND it, and try to get others to understand it obsessively. But the experience itself... I wouldn't be able to type on a keyboard while DP'd as I experienced it. I'd be too busy howling, shaking and clutching the carpet.