Originally Posted by corporate-wage-slave

There are more Habours than Peaks, more Kings than Doubles, so excluding the two ultra suite categories, you're probably aiming for a Harbour and ideally a King.

They are fairly generous with upgrades for Diamonds, from personal experience and judging from comments upthread. In 20+ visits I've always had at least a one step upgrade, and Diamonds are more usually looking at 2, 3 or 4 steps on the whole. In other words you're unlikely to go from a Harbour to a Peak. Having said that I've only once got a suite, albeit from normally booking the entry level room types - the number of suites is quite low compared to the scope for low to high floor upgrades (which is what Executive effectively means). Also the Harbour rooms near the centre of the building (by the lifts) have the better view after about floor 50 compared to the suites, so that may be Plan B. Ask to check in for your room in the Executive Lounge itself, in my experience they do try very hard to get an outcome that you would be happy with in the Lounge whereas on the lobby floor the staff are in a bit more of a rush to complete the transaction.