I don't know the "real" show but they did a few changes. The biggest one - he did not ride on the horse, just walked next to it. He also did not crawl over the audience to get his toilet rolls back. And there were a few jokes about his cousin and that Greg was "Jack 2.0" and also Janet looked under his kilt and said "He's a true Barrowman".
The "12 days of Christmas" were hilarious as well, he was laughing quite a bit. Hope I'll get a chance to see John tomorrow though!
Edit: video with Greg and the 3-D-parts of the show: http://www.youtube.com/watch?v=30pzutKFm7U