So I've now been up the Burj Khalifa...
...to which the thread needs renaming! I'm out here in Dubai at the moment (stuck, incidentally, thanks to the ash cloud over Europe) and yesterday I took a trip up to the viewing deck on the 124th floor.
Some interesting points to note - although the structure is 828m tall and there are 206 storeys (160 of which are habitable - the rest are maintenance storeys in the spire), the viewing deck is only on the 124th floor, and at 442m. There's still a hell of a lot of building above you! The viewing deck is partially outdoor, however - there are massive glass panes in front of you and a solid floor beneath you, but there's no roof to speak of and there are gaps in the panes so you can stick your hands out into the air.
The elevators to get up there are quite amazing. They're the worlds fastest, at 40mph. Strangely though, unlike the one I've been up in Sears Tower, which is much slower, you barely feel it accelerating or moving at all, certainly not on the way up. The only indication your elevation is changing is when your ears start popping.
It's all very tasteful too. You can tell how proud Dubai is of the Burj, and they put a lot of effort into all the information boards at ground level explaining how it was designed, built and maintained.
The sense of scale is odd. Sears Tower felt quite tall to me, but doesn't look it from the ground especially as it's in the middle of a city and surrounded by other skyscrapers. The Burj looks massive from the ground, but then there's nothing nearby by which to judge the scale so you can't tell just how tall it is until you go up it, when you are then looking far down on what, by anyone's standards, are very tall buildings.
To illustrate, this is a view I took from Sheikh Zayed road, the main road running between Dubai's skyscrapers (visible also is the UAE's new metro system, and one of the stations, in the bottom right of the image):
And here is the same road and same skyscrapers viewed from the Burj...
Looking towards the Burj al Arab, the famous 7* hotel. Unfortunately, cities like Dubai are often shrouded by sandy, and probably smoggy air, hence the poor view. Visible behind out into the water is Palm Jumeirah, one of the famous palm-shaped developments. I've driven onto it, and it's massive.
A view looking up from the 124th floor viewing deck:
Views of the Dubai fountain and Downtown Burj Dubai. The skyscraper you're looking down on is The Address, a hotel and residential building. It's 306 metres tall and has 63 floors, which gives you an idea of the scale...
And again, worth bearing in mind that this was from the 124th floor, rather than the 160th, or up on the 206th...
I've got plenty more but uploading is proving slow and painful...