Echo cartos - very good

Agreed. A week so far, on 90% VG 10% H2O juice with 5% flavoring and 10mg/ml nicotine. This is the 510 threaded eGo mega conical metal one. No sign of any problem, incredible draw and vapor. About 2.5 ohms. Simply incredible. Just remember to keep tamping the filler down so it fully contacts the coil. First fill is fastest with a syringe and needle right into the filler on the sides, 2 ml. Simple to keep adding say 10 drops down the side, and tamp the filler a bit, say with a 510 empty cart, every so often. They can feed well for a long time, like during a long drive, but better to keep the filler soaked, swampy, on the edge of overfilling, never let it go even slightly dry. Blow it out if you overfill. I would imagine they'll keep going and going until it's time to rinse and clean. Some do a full surgical rebuild and dry burn, but if they run this good for a month, at $3 each I wouldn't feel TOO bad about just putting a gunked one in the salvation army pile. The plastic mega ego cartomizers were my previous champ, but it was hard to do any maintenance on them, and after a few weeks, as the filler would no longer fully contact the coil, they would start gunking and broiling. These, being so accessible, maintainable and easy to fill, are better yet.

The echo carts make so much flavor and TH that I've had to dilute all my juices with VG to make them tolerable. I'd be happy to post a sparkling review, but I don't see any review options on their product pages.