I've been using OB for bass for about a year now. It's the cleanest bass I've ever had in my house. Like all other types of bass cabnets, it has advantages and disadvantages. The biggest advantage, to me, is the figure 8 response pattern. Energy to the sides of the baffle is neatly canceled out. There is much less room activated bass, thus the bass coming from your speaker is what you hear, not a lot or reenforcement and cancellation waves. Also, lack of box resonance is nice.
Disadvantages include lack of efficiency. It takes either more power or more drivers to get loud and deep. My OB's work well in the corners, so they don't take up a lot of room space.
Dave