I used the PVHE turbo stem made for the Solo through Planetvape with the Air. It really helped with the airflow and with the harshness. I used green temp level with very little irritation and great airflow. I thought I had a turbo GonG but I don't.
I will try out my Solo GonG with the Air and see how hot it gets. More testing required......
EDIT
I tried my 18mm Solo GonG with the Air and it doesn't get too hot. It is more harsh because of the shorter air path. The airflow is better with the GonG and it's not a turbo. So a turbo would even be better airflow. I also used a battery that had been sitting for a couple of weeks and it still had juice left. Not sure how much left because there is no battery indicator.
It would be worth it to buy the GonG IMO. I don't notice any stretching.
** I did notice stretching with the Ed's WonG.