I like the convenience for adding air, and I have not had any trouble with them working.
However, I'm thinking about going back to the stock ones at the next tire change. I had to add several ounces of weight directly opposite the right angle valve stem, and even though a static rotational balance tells me it has the right amount of weight to balance it out, there is a high frequency oscillating vibration at very high speeds. It started when I added the right angle valve stem, and new PR2s. I could wait and see if new tires fix it, but I'm pretty sure it's not the tires.