I've gone overnight in the 777-200 (to Houston from Auckland) in premium economy. It depends how much value you put on sleep and what the cost would be to freight the rest of your things over.
With the overnight flights in PE, I'd watch a movie, eat the meal, then sleep till lights came up before breakfast. Best flight sleep ever! But, that being said, I got to the same place at the same time (just better rested and possibly better fed).
When I've done similar flights in economy, it's been more a case of dozing on and off all night but never getting restful sleep.