It was wonderful, in parts. The West End part was really beautiful and I definitely will be going again. Loved Leicester Square and Piccadilly in particular.
However, I went to the King's Cross section one evening and it was a nightmare. The displays were located in the narrow section of lanes and new buildings just to the west of the station. Even though I arrived early the crowds were too large for the space and security gradually closed off some areas, as the congestion was becoming increasingly dangerous. People trying to get back to the station area, having seen the furthest displays, were therefore forced into one alley, making that section even more congested, especially as they were fighting against the people trying to head towards those displays.
Management then seemed to switch off some of the displays (as a safety measure I suppose?), but did not make any announcement (that I heard anyway), so some of the crowd who would have viewed the displays and then left, were instead just hanging around to see if the lights would go back on, leading to even more congestion.
They then closed the tube entrance, causing the large crowds to be forced to walk along Marylebone Road when trying to disperse. Passing buses could not cope and so were not able to pick up most of the people at the bus stops and most eventually walked on to Euston etc, en masse.
So basically, I went there, got squashed in an alley with a mass of people, didn't see most of the displays, took ages to get back to the tube station, which was closed, waited for a bus, which did not stop, and then walked on to Euston. Very frustrating evening. Hopefully they will re-think this section of the event this time!
I didn't experience any issues at King Cross, although I was there around 4/5pm so its a shame to hear how bad it got later into the evening. The queues at Grosvenor Square were huge though. I was put off by them so didnt bother queuing, after making the walk over to that area for that one attraction it was a bit of waste of time. Leicester Square was a bit mad too, I think they needed to limit people into the Square itself and maybe direct traffic, so it was separate entrance/exits (or did they do that?) I'm sure with a year out they will have been able to address issues in planning and crowd management. The crowd management on Regent Street was notably impressive I thought.