I love wood floors. There are a ton of options for hardwood out there on the market. You can even find some great stuff in salvage warehouses. We have three different species in our house and this one is by far my favorite. It's 2-1/4" White Oak No. 2 Common. It's not the lowest grade but just one step above. They wouldn't sell me the lowest grade because they thought I would come back complaining that it was so awful I couldn't use it.
I told my installer to basically just throw it down. I didn't want him to fit it super tight nor did I want him to fill any holes or knots. Call me crazy but it worked, we saved a ton of money and got a rustic look. The wood was very inexpensive and beat up (basically because no one else wanted it) and I didn't want him to make it look polished. He did a great job and we love it.