If you ask 5 different people you get 5 different answers. I would say the top serviced apartment in HK is the Four Seasons. Not sure who would get spots 2 thru 5
Price is the only real indicator of quality... with serviced apts the cost generally correlates with quality because unlike with hotels where people come and go people will stay for long periods in serviced apts (or quickly move if the prices are not competitive...).