No, I haven't taken 2C-B without moclobemide. However I would assume the longer than normal duration is due to the MAOI. I never had such long durations with psychedelics pre-MAOI. Then again, there is considerable individual variation anyway!
If you're interested, I've taken a few other psychedelics on 600mg daily moclobemide with interesting outcomes:
4-ho-met: 8mg oral was a weak/normal trip, 15mg oral was a very strong (fun) trip (and lasted 8-9 hours to base)
4-aco-dmt: 7mg insufflated was a very strong, very visual trip (unexpectedly and uncomfortably so)
DMT: 20mg vaped was a breakthrough trip and lasted 40 minutes (instead of usual 5 mins) with afterglow for 3 hours (beautiful)
LSD: 150-200ug - no increase in length of trip but very strong visuals compared to what others report on similar dosages
AL-LAD: 225ug - similar to LSD but even more obnoxiously visual. Had some lasting visual artefacts a few weeks after this (snow, halos, tracers)
MDMA (very dangerous with an MAOI!) - 80mg - strong stimulation, at times uncomfortable, very harsh crash, no increase in length of trip (DO NOT DO THIS)