what makes this a whitewater-specific PFD? I'm looking for a low-profile touring PFD, is there any reason this wouldn't work for touring? thanks

The impression I get is that touring PFDs are built for all day comfort, whereas whitewater PFDs, while maintaining relative comfort, are also focused much more on mobility and safety, meaning extra features that ensure the vest wont ride up, extra wide arm holes, etc. That being said, I don't see why this particular PFD wouldn't work for touring. I would take a whitewater specific PFD touring, but I might not take a touring specific PFD to the creek...

The only thing that makes this a whitewater PFD is the amount of flotation. I personally own this vest in black and have used it for the past 5 years and hundreds of days on the river including two trips down the grand canyon. It's the best one I have ever owned. I would say this would be a great choice for a touring vest. It allows free and easy movement while being extremely comfortable.

The whitewater classification is because of the additional features that keep the jacket on you in churning water. Note the additional clips and 'grippy inside'. You can certainly use this for touring without problems as it has a low profile and back.