I've been using a EMDCC for about a week now, and I'm pretty happy with it. Mine is on a 1000 mah eGo battery.
The ones I ordered at first had the nipple tips on them, but I wasn't very happy with those. I ended up needing to order something else from MadVapes only a few days after these came in, and that's when I saw the whistle-tip version, so I ordered a couple of those. Now I'm using the original EMDCC, but with a flat-tip pilfered from the new order (which just came in today.) The whistle tip is much better, IMO.
They hold a lot of juice, and they give a good vape. The one thing I don't like is that I can't seem to find a way to refill them without it leaking. To deal with that, I take it off the battery when I'm refilling, and make sure I've got napkins or Kleenex's or something similar around.