I do not have an A2.
I've got a Strion lamp mounted in a Scorpion socket base, installed in a bored out Brinkman Maxfire. It runs on a single 18650 cell, and makes a perfectly acceptable beam. I'm pretty sure the whole thing cost me a lot less than either a Strion or an A2.
I have a ExE series Surefire head with a Lumens Factory lamp (EO-E1R) on a TranquillityBase E series 18650 body. This is one of my favorite lights, and I'd highly recommend it to anyone. The trouble is finding a TB 18650 body. Even with the cost of the TB body, it don't think it cost (much) more than an A2.
I do not own an A2, and I doubt I ever will. It's a very tempting light, but I'm not too keen on anything that can't take a rechargeable cell. I know some people have had success with a pair of R123A cells, but the runtime looks poor and there are concerns about the increase voltage vs. the LEDs. You can retrofit the LED ring, but... by this point, it's just too much trouble.