My T3 seems to gurgle and leak when fluid reaches 1.4ml and under. Before that, works great! Any way to prevent this other than adding fluid, which isnt practical if out and about. No air-holes are covered, and it is a SI T3 on a volt X2 battery.
When your T3 starts to gurgle and burble, you can either cast a spell with the resulting potion, or tip it up and vape it to get the extra juice out. I think it may be a combination of condensation and extra vacuum with there being more air in the chamber. If it gets really bad, and I'm outside, I give it a flick to clear the juice. Centrifugal force is a good thing.
From the handful of brief reviews people have posted of their experiences with the Evod, it would appear that people are getting a better vape from the Evod than from their T3s. I haven't tried the Evod myself but have used T3s a lot. With the Evod, instead of replacing the base you can just replace the atomizer head portion of the base which means the replacement heads are cheaper. Although rather similar in appearance and overall form, for whatever reason (that I haven't heard nailed down yet), people who have used both prefer the Evod.