I have 3 minis. A version 1, a version 1.5, and a version 2. The difference is the juice and air flow. The version 1 had the juice channels at the bottom of the chimney and a single airflow slot on one side. The version 1.5 had a slightly better juice flow slot in the bottom of the chimney and added a second airflow hole on the base. The version 2 had the version 1.5 airflow base but moved the juice channels to larger holes in the side chimney. Rip Trippers had a great video on how to wick the subtank mini, you just have to get past the theatrics. Not sure if he updated it to include the version 2 with the holes on the side of the chimney.
The deck itself hasn't changed. It's really easy to build on, wick, and use.