I flew it (on Lufthansa) for the first time on my way back from Dubai (via Frankfurt) yesterday.
Other than the fact that it is a large, double-decker aircraft, there really isn't anything special about it.
Especially if you're in economy class. You're packed in like sardines, regardless of how "big" the aircraft actually is.
And, although I know it's not Lufthansa's fault, the angry toddler two rows in front of me that screamed throughout the *entire* ten-hour flight did not make the experience any more enjoyable for me (or, for that matter, anyone sitting near me).
To sum up: it doesn't matter how big or how new or how nice the aircraft is. Economy class is going to suck regardless. If you (or your employer) can't pay the big bucks to fly overseas in business class or first class, you're going to have a lousy flight.