Whilst I have usually had a fantastic experience with ex-LHR staff (on 747), my recent A380 flight in F ex LHR was a bit of a disappointment. Staff were friendly-ish but poorly trained and seemed not only to take orders from the menu poorly but also forgot things.

My ex-SIN segment was significantly better with the crew doing everything possible to make the flight a memorable experience. Also the loo was kept spotless which always makes a difference especially when you get some passengers who don't seemed to be properly toilet trained.

The crews I spoke to on the Aussie segments did mention that they were doing a rotation in LHR to try and help lift the service levels so hopefully that will help to alleviate some of the service issues experienced by both the OP as well as other passengers like myself.

Personally I found the toilet good, but I still have to say I prefer the 747 loos. SQ A380 wins hands down in this respect (although I prefer the QF A380 seat and service wise). In respect to the amenity kit, I actually quite like them but perhaps that is a matter of personal taste.