I have a Kona Dew, which is the same geometry and frame as the PhD, but lower level of componentry.
My Kona has done dirt, gravel, grass, and asphalt. I rode it in a triathlon, too. It is a fabulous all-round bike for me.
My kiddo decided he wanted it when he outgrew his bike, so I just gave it to him and bought myself a Kona Smoke this afternoon. Now we're a two-Kona family!
Kona is based here in Ferndale, WA. They do a lot of outreach to kids in need (including kids at my old Junior High), and did a huge Bike Town project with AIDS workers in Africa. I'm happy to support Kona. And their bikes are very decent for the price. As my LBS says, they're "bombproof".
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson