Here is a link to some info you might want...

http://www.overgrow.com/edge/showthread.php?t=656368

But I will save you some trouble, if you look at the Dome Vaporizers section. (Dome-style is the one you are considering). Right there it says "Worthless. Don't bother with it" But you can read reviews of all vaporizers right there. Hope that helps.