I agree. I've tried them all and IMO Iwata is the best. My HP-CS is also a little fine for something as big as a tank, and I've been thinking about getting a siphon feed for the added capacity, and when I do it will be an Iwata.
This is the one I have my eye on
http://www.merriartist.com/Iwata_Ecl...FQEcaQodjkoAYA
It has the option of a one ounce siphon feed bottle and though an ounce doesn't seem like much, it will cover an entire tank with an airbrush.