My regular flights always include a ULH leg (based in Australia) and so I almost always make use of the shower if I'm travelling F. If I'm connecting to a city on another 380 in F, I still like to shower towards the end of the second leg because I'll have slept and want rid of that horrible 'just landed' feeling one gets from aircraft cabins.
If I am connecting onto a 777 after flying on a 380 I notice two things. Firstly, the noise from air rush/engines is noticeably louder on the 777. Secondly, the air is dryer and the relative altitude is higher on the 777 (8000ft v 6000ft A380). It doesn't mean much if you're off on holiday, but if you're doing these routes a lot its a big difference.
My favourite frame right now is the 787. Humidity, pressure and cabin volume are excellent. Some silly decisions being made by airlines at the moment about layout and routing though (ahem, QF PER-LON and QR Y).