Yes, I have A3 but... Somehow it "feels" a bit to small to operate by one hand with ease.
I had the A3 and though I really liked that light, I didn't resist when my sister asked for a keychain light. My one complaint with the light is the lack of grip...I wish the knurling was similar to the maratac lights.
With that said, I'm seriously considering the A1 light. CR123 lights are my favorite format and I just love the size of that light. I have the quark mini 123 but. I'm thinking of getting the ITP light in Stainless...the only holdup, is the fact that I don't love twisty and that this particular one does not have great knurling.