I love my Airvape X for a variety of reasons, but the blue color is still at the top of my list
It does get hot, that's for sure. I use silicone rubber bands just above the display for better handling.
As far accessories go, the glass adapter is by far the game-changer. It opens up all sorts of options. It makes for the most elegant dab-rig without all the torch-douschyness (IMHO)
To that end I think a re-designed adapter that slid through the metal lid-top would make for a much more secure fit instead of relying on the rubber seal around the mouthpiece.
Also, being able to flip the display would be grear