The 747's tail does "cork-screw" for want of a better word. Some people are sensitive to it, others aren't, its basically motion sickness. I've never had a problem, don't even notice it; on all versions, 1-2-3-400 and SP. -F/SF versions (barring the SP) too.
I've been told the 777 is worse (I've never been on a 777, so can't comment).