I get a chance to travel Club World once a year with BA, and I always choose upstairs on the B744 (four of us travel together and we always specify upstairs at the time of booking to avoid disappointment).
Frankly, even though someone else is paying the bill, I'm not all that bothered about First Class - with Club you get excellent service from top-class staff, and a lie-flat bed that even my 6'2" frame can get reasonably comfortable with. I've been bumped up to First with American Airlines in the past and it was nice, but not all that much nicer than the AA Business Class I usually used.
I'd quite like to try Virgin Upper Class sometime; looks pretty cool, but I've only ever managed Premium Economy.