Just finished MIA-PAR-BOS on AA Premium Class with its fully reclining seats. The service and comfort(s) were wonderful. This was a rare treat for me as I usually fly Bus on AA to Europe. AA Bus class is adequate and seems to be better than most carrier's business class. However, on many other trips I have flown Delta Bus Elite and found it to be more than satisfactory, in fact superior to any bus class seat I have ever flown in. Given the difference in price, I find the quality to price ratio to be superior in the Delta Bus Elite seat. In June I flew NWA Bus Class to DTW-HKG-DTW and found the service adequate but not quite as good as the Delta Bus Elite product. There was less room and a lower level of service.
I have also flown BA MIA-LHR-MIA in business class and found it to be sub-standard. The seats were nowhere as comfortable, nor was there as much personal space as on Delta. The level of service on BA was also sub-standard and inferior to any other airline's business class that I have used. My sole reason for flying in business or first is the extra space and comfort they offer and if I can find it for substantially less in business class that's where I will spend my dollar.