I used the Yosemite guides for a day's climbing when I was there and they were great. My guide - Bill - had done some gnarly first big wall ascents but gave me a superb day's entertainment on multi & single pitch climbs. He was really enthusiastic, pushed me quite hard and full of stories. At the end of the day we went to Yosemite Bridge to see who was on the big routes and he called one of mates who was up there for a chat! Great day out.