I went up the MBS and yes I thought it was a rip-off, but like most people who go, when you've got friends visiting, you pay for these things.
A couple of things annoyed me (apart from the price which I think should be about $5) - one was that they didn't seem to have a limit on the people they were letting up there and it was packed by the time we left, another was that for some weird reason, they were letting us, the visitors, into the pool deck area which I thought was totally out of order - there were guests sitting in the jacuzzi having a drink and all these families posing for photographs next to them

and I thought it was pretty bad for security too - anyone could have whipped someones room key or belongings. This was a while ago now though - hopefully they've sorted that out.
The lobby of MBS was as busy as an MRT station too. I wouldn't want to stay there, it's quite tacky really. When you go in the mall, it's almost empty apart from the food court area which is busy too............makes you realise just what the average person around here craves ......and I don't think it's a Hermes scarf
I've been to the Altitude bar up on the building in the CBD and I do prefer it to MBS - you at least get a drink in with the price and there are less people up there. I don't think it opens until the evening though so you can't take sunset pictures