I was in HKG the last weekend for 2 nights and got upgraded for the first night as the superior room was fully booked out. Got a premier room on the 14th floor and it didn't appear (at least to me) to be significantly different from that of the superior room.

I was given the offer to change to superior room on the 2nd night or pay HKD440 (nett) for the 2nd night to be upgraded to premier room as well. Offer included breakfast for two persons for both days, free internet access and access to the Premier Centre on 15th floor. However, due to the tight schedule, I didn't really utilise the benefits given. I just paid for the upgrade to avoid the hassle of changing rooms, that's about it.