But, the machine work on the body and threads was jagged and sharp. I would have really liked to have had a choice in the McClicky press weight. It seems to be rather hard.
Also, the light gets really hot. Like... really really hot when it's on high.
... I would have rather bought a surefire and a Nailbender Nichia drop-in. :/
I only have one MDC body, but the machining on my example is done extremely well, with all edges crisp and straight. I suggest you try another one, since yours doesn't seem to to Gene's typical high standard.
Gene uses the same design for the MDC tail as the MD2 tailcap. The o-ring located outside the switch boot is easily removed, and then the boot itself can be pulled out. The outer flange of the boot is slightly larger in diameter than an Oveready McClicky switch boot, with the silicone SoftPress boot being larger than the others. The SoftPress boot drops right into the body in place of the standard boot, and the o-ring goes neatly into place. The smaller flange may slightly reduce the water proofness of the light, but it definitely makes the switch easier to press/click. My body, with E2/Scout head is sitting on the bottom of a large plastic water bottle at the moment. I don't expect any water intrusion.
It's a 200 lumen light that is quite small, yet your'e surprised that it gets hot? My M61 219s get quite warm in Surefire 6P or MD2 bodies, which have a lot more surface area than an MDC.
An outstanding benefit of the MDC, as you mentioned in the first sentence of your second paragraph, is the small size that makes it disappear in a pocket. It's considerably smaller in diameter and length than a Surefire 3P with Z44 head, so that's hardly an appropriate comparison.