Here is a comparison photo of 3 hydratubes from DHGate. These are: (from left to right)
-yingmin's new and improved matrix Hydratube
-yingmin's first and smaller matrix Hydratube
-Stevenlmz's Hydratube
As you can see, the newer hydratube certainly blows the smaller one out of the water, you can actually take bigger hits without water splashing up into the hydratube and misting into your mouth/lungs. The problem with the smaller one is that its water chamber was based off the size of Steven's because they're almost exactly smaller. But with a matrix perc, the bubbles stack much more, causing it to go up the mouthpiece.
For $33 its a bargain. I feel sorry for the people who are still purchasing the mini-Hydratube because its $8 cheaper.
http://www.dhgate.com/product/new-big-vapexhale-hydratube-with-1-birdcage/388109628.html