My brand-new B40 worked great the first cup. On the second cup, everything went normal, but only about an ounce of coffee dribbled out. Talked to tech support, and figured out that you really do need to equalize the pressure in the K-cup (I'm at 6000' in Colorado) by pushing the K-cup down onto the needle in the bottom of the holder. If you don't, the K-cup will/may equalize the pressure through the top needle, sending coffee grinds into one of the three holes and clogging it up. Used a paper clip to clear out the three holes, ran a few brews of just water, and now it works great again.
Recommend this product?
There is an FAQ related to this on their website about pre-puncturing the k-cups at higher elevations, but it doesn't tell you what to do to solve the problem.