Heyas leakingb,
I tried the ego-t tanks, and soon gave up on them due to the flavor issues. They were very convenient to fill, but convenience with no flavor just didn't work for me.
The ego-t batts are great though. Lots of different options. If you want the capacity of a tank, you might look into carto tanks. They can be had for ~$10 on up. And I've seen them with up to 7ml or even higher capacity. The tank part is indefinately reusable, and the carto's don't seem to need replacing any more often than a carto without a tank (although I'm still new enough to carto tanks to have no direct experience of longevity). They're not as easy to fill as an ego-t tank, but flavor/vapor/etc seems just as good as a normal carto.
Maximillian the Vaguely Disreputable