I usually pump for an hour in the morning. I have my coffee, surf the net and just leave the pump at my side. When I think I could use more suction I pump a bit more. I don't use as much as I should - I would like to use it consistently in the morning and night for at least an hour. I think the pressure is about half of what the BB is, and because you can control it it's not painful. The BB forces your tissue to stretch, while the NB lets the tissue "rest" and adjust before the next pumping. The swelling is about half, but seems to retain longer over all compared to the BB.
I used to wear Brava for about 12-14 hours per night. I would come home from work and pretty much put it on right after my shower. I practically lived in the thing! If I was home all weekend I would wear it for 20 hours with a few hours in between, but it didn't seem to make that big of a difference, so I think your theory is right: less wear time & shorter breaks vs. continuous wear. The swelling didn't last any longer and they didn't seem a whole lot bigger. I used the airlock for all 3 cycles and never had any problems. I may have broke a seal a couple times altogether but that was from excessive movement. The domes stayed tight all night, plus the extra suction was great for domes that were getting worn out.
I used the massage setting with BB. The suck was just too much. And I used at about 3/4 suction. I used it for 3 cycles of 8 weeks, once per day for an hour. I tried doing it twice a day, but it was just too much. I used it in the morning - for some reason I got the best swelling then!