Although they were new to fly fishing, they weren't inexperience anglers. They hooked plenty of fish and had to work for them- making repeated casts with sink-tips and working streamers most of the day. Anybody who has done this type of fishing knows that it will wear you out much quicker than watching an indicator keep pace with the boat all day and making a few mends every now and then.
These guys were great, good humored, patient, willing to take advice, willing to work for a hook up, enthusiastic, and experienced enough to know that not everyday means catching every fish in the river or setting a new IGFA record (although I will say they did hook and land plenty of fish). And also to their credit, they even took the time to practice some fly casting before showing up. In short, these guys rocked, the kind of people any guide would be psyched to spend a day with.
I get to fish with a good mix of people with a wide range of experience levels. I'm sure for some, it may be intimidating fishing with a guide for the first time. It shouldn't be. Keep it light, keep it fun, be willing to listen, and understand that fishing is, well fishing. There are no certainties. In short, be like Mark and Rich.
Here is a great article from MidCurrent on the "Do's and Don'ts of Guided Fishing Trips" . It's worth the read, and full of some sound advice.