I have the Delta 23, and it's my favorite tank, been hoarding coils for it. Vapes hard, strong clouds, strong flavor. Usually vape at 17-22 watts depending on eliquid. Current coil in it has gone through 24ml of liquid, and still vaping strong, tho yes expensive, the coils are well made. It mated with my evic supreme is my main device. (Knock on wood) so far not a dry hit, a leak(aside from pressure changes going up and down a mountain that all tanks seem to have) nor any other issues. The tank seems well made. Wouldn't mind picking up a Delta 16 for my smaller devices.