I've done every one several times, but yeah, not in one session, especially with Ao3 in the mix.

I try to do a series of low level campaign every other session or so. (No clue why. Maybe to remind myself what they're like. Maybe to finish quests. Maybe to run my lowbies through. Maybe to meet new people. The new people don't seem that annoying. They're helpful actually.) Swamp is slow if you're alone; well, not sure since I haven't taken a 50 through there yet. It was very fast when they cut out the Boss Brawl for a period of time there. Ao1 through Ao2 is fast, then of course, Ao3, you'll need a team and this will probably end up being several teams since it takes some time.

Doing a whole campaign is great fun. I did not realize this was a rarity. It seems like lots of people hit the NEXT LEVEL button...