So you get what you pay for. All the HK retailers large and small are middlemen getting the same product from the manufacturers like Sony and LG, and for large items like TVs they all use the same installation companies. But large shops like Fortress and Broadway will probably have larger warehouses (and better control of stock) and probably better followup.
So nearly three weeks later, the TV is here and installed, but it's been a headache dealing with the small retailer and also the installation company. As with all home deliveries and installations in Hong Kong, it will ALWAYS be at least an hour later than the time range they promise to show up at your flat.
Hopefully there's some small electronics retailer out there with great service but I would not expect it.