Apart from a 45 minute stand outside in the rain the actual interview process was pretty much as I expected. It's a pain not to be allowed mobile phones or I players but the local chemist down the road (Goulds I think) looks after them for £3. Interview was scheduled for 8.30 and I left the embassy with an approval at about 11.40.
Take something to read as sitting waiting can be boring, although you can buy snacks, tea coffee ect.