I've moved a Blast City and NNC tube by myself. My Windy tube is a bitch when you're alone. As I've said before -
"Satan's Arcade is filled with Konami cabs."
And I mean it!
To answer your question: The key here is the metal frames on the tube. Sega cabs have them behind the tube, and are easy to grab. Konamis typically have less support in the back. (With Beatmania being an exception, this has a frame.)
It really depends on how far the tube is going. If its close by (ie work bench), I lay the front of the tube against my stomach and grab the metal frame. (This is a Sega cab, mind you.)
If I have to go downstairs or outside of my work area, I'm definitely using 2 people. Anything with a rotation mech is needing 2 people as well.
Like others have said, always use 2 people to be on the safe side.
I've never attached any ground wires to my tubes outside of the cab. The NNC is full of them too.
I have however laid a tube face down on a soft pillow. Upon moving the tube, that brief sliding on top of the pillow caused the tube to gather static electricity. I was surprised at how sensitive it was.
Color me paranoid, but I make sure to discharge after I move my tubes around after that experience.