It used to be that case that the 747 was the top rung of an airline's fleet and the recognition in Ts and Cs were appropriately high. But since old 747s could be bought for next to nothing and converted to freighters with ease, the glamour has gone.
Sure pilot's want to fly what was the biggest airliner in existance. Perhaps it's because it is so big and has a deserved reputation for being a nice thing to fly. But the novelty of flying any aeroplane disappears after about a thousand hours, then you are left on a ageing aircraft which has more than it's share of age related problems, flys for far too long for comfort and some of the 747 operators mentioned on this thread aren't the employers of choice!
I've flown the Classic and 400 on both pax and freight routes. I would be happy to never fly one ever again. Now I'm on more modern narrowbodies on short haul routes, I'm a lot happier.
Go for lifestyle, not the aircraft. In my company, the 747 pilots are the worst paid!