Interesting about the noise mentioned by wacbzz. I've had my Preon 2 for about a week now, and have used it plenty (I just changed the original batteries out today). I never noticed any whining from it. I did just stick it in my ear while it was on to see if I could hear anything, and could faintly hear a dull whining at the emitter end. The heat it produced was pretty impressive though, I must say.
It was my six year old daughter that first noticed the noise. Before I took the photos, I took the light out of the package and gave it to her (she has one of the 219's and my wife has the other for work). Not ten minutes after she had it, she came back to me and said "Here. It's making a noise." Sure enough, it does on both high and low. Some folks are really sensitive to PWM but I am attuned to the (not so) subtle noises.
I really like the new design of P2 though. I find it to feel much better in the hand. Now, I'm just hoping Craig orders some of these with the 219 in it.