Just back from the trip, it was fantastic. I'll post a review later, and some pics when I sort them out, but if anyone is considering this, just do it!
We encountered no trouble at all, and the anti-western feeling the FO warned about just wasn't there. Everyone we met was lovely, apart from the staff of one hotel who refused to change my Scottish banknotes - awful warning!
We were in fact very lucky, there were few parties there, so we had the sites to ourselves, the people were grateful that we had come, and prices were low.
Amazing trip.