I have found that service depends on how busy the flight actually is. If the cabin is full then service does drop off, but if there are open seats then the crew are more relaxed and seem to provide better service. This would be in business class.
Funnily this seems to be the opposite in economy class, where if the cabin is full the crew seem to be more up for the service, but when it is relatively empty they seem to relax and their service standards drop. YMMV.