As a few have said, not all artificial turf is the same. Not all dirt facilities are the same. The NADAC crew did a great job of raking the weaves, and other areas that needed attention during the Champs.
From my experience judging and watching dogs run on various turf locations, I have witnessed many dogs slip and fall on turf. I have also seen dogs slip and fall on wet grass. Both can cause injuries. I don't see a lot of dogs slipping on dirt but it depends on the type of dirt surface. A hard packed surface with grains of sand on top can be quite slippery for both handler and dog.
Many of the highly competitive fast NADAC dogs have handlers that refuse to run on turf due slippage and injuries. I have spoken to many handlers of very fast dogs and they all say the same thing...no way would they run their dog on turf because of the slippage issue.
Another thing I have witnessed while judging, when big fast dogs run on turf for the first time, and slip on a turn, many will then go into self preservation mode and will slow down to prevent injuries. This in turn leads to lower YPS for those dogs. I have also watch many videos of dogs that I personally know and have noticed how slow their runs are on turf vs dirt. A huge difference in DRI's.
I can't say all dogs will slow down, some don't care about their bodies and will run and fall a lot....which makes me cringe when I am judging. What I have witnessed is those teams are not longer running at those facilities when I come back to judge there. Either because the dog has injured himself, or the handler has realized the dog is not taking care of its body and the handler must do it for them.
On the other hand, I have heard from a lot of small dog (4'-8")) handlers that love the turf because of the levelness of the turf. Their dogs seem to run faster on turf.
So I think there are some pros and cons about turf vs dirt, and IMHO it depends on the size and speed of your dogs.
