I've used the long 3D stem since getting my TM2, and it's pretty perfect. But this might just pip it. They're actually equally good at cooling the vapour, despite this one being half the length. But the long 3D stem is easily broken (I broke my first one by dropping the vape from height onto carpet! And the second one while cleaning it the same day that this Shorty stem arrived coincidentally enough. I'll probably get a third one, it's cheap enough. But this Shorty is amazing.
Firstly it's just a much more convenient length which makes the whole vape more portable and less prone to breakage. Not that it's not gonna smash if I drop it in my goddamn porcelain kitchen sink (bad idea), but in use it's much more compact and less likely to take a knock that'll smash it.
Secondly it's about as good at cooling the vapour as the tall 3D stem, surprisingly. I gather it's something to do with the surface area of the ball as it rattles around during a pull. It's not loud in use though - although it is if you shake it.
Thirdly, the shaped mouthpiece is perfection. It just feels right.
GET ONE.