After a lot of practice, I can consistently go for 1 hr 20 min, and I pretty much do it that long every time I masturbate. I call it "doing my penis exercises"
One difference is that lately when I jack off, I don't usually ejaculate...Mostly just go for a "dry orgasm," which I learned from the book "The multi-orgasmic man".
I have gone for longer, probably about 3 hours, usually when stoned or drunk ( or both ). But I've never had a dizzy feeling when coming...I have, however, had a few "strange cums."
For example, one time I had just started back up again after an edging break, and felt like I was gonna pre-cum, and instead a huge stream of white cum poured out all over my cock. It was strange because it didn't necessarily feel good like an orgasm, and my cock didn't go soft afterwards. I went on to have a nice long jack session with another, real ejaculatory orgasm after that. I just used the first ejaculation as lube!
Another time I experienced multiple "wet" orgasms, like the poster above, and I felt like I could have just kept going and going, with the appropriate amount of time in between, staying the hard the whole time. Eventually I just stopped and went to sleep out of boredom!
I love edging, and it's fun to talk about it...
Keep up the good posts guys!