I've hired a guide twice, once in the Smokeys and once in Yellowstone. Both times were enjoyable. The guide treated my son (12 yrs old in Smokeys and 14 yrs old in Yellowstone) with respect and acutally gave him more attention than they did me. As his dad, that is what I was hoping for. They both were rewarded with good tips.
The guy in yellowstone even had a mishap with the shuttle service that took his truck and trailer to the pull out point. When we got there, the keys were not in the box under his bumper. He had to call them and it took about an hour to show up with the keys. Instead of being upset about it, we all went below a nice shade tree and talked fishing. My son and I waded out in the Madison a little and fished. The guide had some candy in his pack and gave it to my son because he was hungry.
When he learned we were going to be fishing a few more days, he got out his map, marked a couple good places to fish inside the park and gave us a handfull of flies he thought would work.
The time in the smokeys was our first time fishing there. I told the guide that we were more interested in learning how to fish there than catching a bunch of fish. He did put us on some really nice fish but he listened and spent most of the day talking about how to read the water, hiding behind rocks and high sticking, approaching the water, etc. Basic stuff but to a newbie it was good information and helped establish our baseline for fishing the streams in the GSMP. If memory serves me correctly, he also handed us a bunch of flies at the end of the day.
I'm sure either of these guys could have been surly on a bad day. It does stink though when you spend good money and catch a fellow on a day when he got up on the wrong side of the bed.