I have a Little Giant and would never buy another ladder (and probably will never have to). It's just so versatile. I could go through all the things it will do that a regular ladder won't (or won't do safely), but their website does a good job of it. Is it expensive? Yes. Is it the last ladder I'll ever buy? Probably so. The only other 'ladder' I own is a step stool - the Little Giant will do everything else.
It is a little bulky compared to say a 6' safety ladder, but it's easier to maneuver than a standard ladder of the same extension.
And, IMHO, get the actual Little Giant. I tried the different other versions out there (Gorilla, Werner, etc.) and none of them compare in any way shape or form. I got on a Werner that was set up as a 6' safety ladder and it scared me to death is was so flimsy. I can't imagine it in an extended layout.
It's one of the few products I own that if it was ever stolen, I wouldn't even look at other brands. I'd just go buy another Little Giant.
You can buy them on-line or Sears carries them now. They always have some special deal going on (free shipping, accessories, etc.).