Everyone seems to be loving the Nautilus Mini's these days, but I bought 3 and they have been pretty temperamental. If every magnetic force in the atmosphere aligns and I put it together just so, it works great without gurgling, spitting or flooding.
On a whim I picked up a couple Protank 3's and several Protank 3 Mini's in various colours and I am loving them. I get consistently good vapes, no flooding, no leaking. I use the larger ones on my iStick and the mini's on my ego sticks.
I'm sure the technology in the Nautilus Mini's are superior and I'm probably just a dork not using them properly, but I have much more luck with the PT3's.