Yeah, I also had a wee look at both Vertigo and Sorrocco, both very nice venues and quite expensive, even for us farang. That all being said, looks like it best to take note of a few things before you venture there.
A) The weather conditions..... You'll not have a nice meal under the stars if inclement weather is on the go (rooftop closed)
B) Book in advance, either by phone or online..... Surprisingly both are popular and get full quickly.
C) Be very ready for a hefty check-bin for either chosen rooftop dining!!!! (as previously stated in the thread)
All that being said, it really does look like a magnificent place to take a chick, LB, your friends or mum and dad for that matter. I didnt do it this time, but I very well might do next visit..... Even if it's just for the experience.
All the best lads
Jacko