Around here, a good climber is some-one who gets a tree down fast without breaking the crew, himself or property.
The faster the better and the more you'll pay them.
A good climber will get around a tree fast, agile, know his cuts and the way timber behaves. will be able to turn it, land it butt first or flat or tip first.
In my time I have had many climbers, but at the end of the day I have seen great climbers with crap saw and rigging skills .... and when 90% of what you do are TD's you need those skills. So not many fall into the extremely good bucket .... but those that do can earn around $300 to $500 a day.
A recent article by Bill Goddard in the Arborage here explained the climbers attitude some.
They're detached from the team in their work environment.
They're psychologically pressured to perform, especially when looking at a bunch of ground crew who have their arms folded chatting.
They exert themselves continuously, even having a break is not 100% comfortable.
They're goal is to get out of that tree ASAP... aching feet/legs, sweat, continually using micro muscles for balance, wind etc all have a lot larger impact up there then when on the ground.
They generally want to call the shots but ground coaching is appreciated however in many crews rarely forthcoming.
If you are having trouble with your climber I found they're most susceptible to listen when you are in the tree with them .... get on their level.