All of mine have the hole in the center and I've bought from several different suppliers although I haven't bought them recently. I know D&B was selling the one he called stealth but I didn't get any of those.
Tony at cropduster has them ECH0 1300 Chrome - $44.95 : Cropduster901!, Home of the B-52which site has the 1300 mah ones in stock?
I've always filled both the single and the dual cartos with a syringe and I've never had a problem. If you slide the needle in at the edge it shouldn't hit the coil at all.I prefer the single coil echomizers and use a 3ml syringe to fill with Boba's. I'm guessing that technique could not be used on the double coils. I've even managed to break the coil on a single with the syringe so I fill them very carefully.
Janty just came out with a neo classic auto. Just saw the promo.It has its own tank system, and adjustable air draw. I wonder if our beloved Echos are going to have some new competators?