I have a blackburn TPS-2 and I have trouble pulling the head away from the valve stem on prestas. I haven't tried it on a schrader yet. Plus, the thing is hard as heck to pump up to even 120 psi! It's easier just to use my road morph...
I got it a few weeks ago on performance or nashbar for about 18 bucks and I could probably still return it but I'll spend atleast 5-10 bucks in the shipping there and back if I want to exchange it for a joe blow sport or a different topeak pump. I'll probably just sell the pump at college after using it for a bit. I figure I'll get about 10-15 bucks for it. In hindsight I wish I'd spent the 5 bucks more for the topeak pump. My loyalty is with topeak as far as pumps go.
I thought I'd get the blackburn since I have one of their multitools and it's pretty good, but I don't think I'm going to get a blackburn pump again.
Sorry for the ramble/rant.