We did it with my brother on our 2011 trip. We got Patrick, and he practically frogmarched us round! I would have enjoyed it if it hadn't been for his barking at us all the time. Far from answering our questions, he would just ignore some of them as if they hadn't been asked. If you don't know the answer, better to say, "Sorry, I don't know that" or "I can't tell you that". It's rude just to ignore paying customers!
I think there were too many people on our particular tour - nearly 20 - and it was a logistical nightmare. Also, there were some ex-CMs on the tour, and he spent altogether too much time favouring them and ignoring us.
We had to wait outside CHH until we were told our lunch would be ready for us - and then by the time we got in and sat at our tables the food was lukewarm. We only had half an hour for lunch, which wasn't a long enough sit-down - and then he kept hassling us to hurry up with the restroom breaks so he could get on. Yeah, but the queues in the ladies' restrooms can be phenominal sometimes.
The biggest annoyance was having us stand in the full glare of the sun for over 20 minutes while he went through every single thing to look out for on Haunted Mansion which we were about to go on. My mind was wandering ... and then by the time we got in and on the ride I'd forgotten everything to look out for.
The utilidors were interesting (not so sure about his obsession with the way they dispose of garbage), and I especially found the video we watched about the fireworks and the laundry/costumes fascinating. The 40-minute stand in a packed corridor with nowhere to sit, on the other hand, was excruciating!
I'm glad you're not supposed to tip the tour guides - because he certainly didn't deserve one!
All that said, I'd do it again - with a different tour guide.