Interesting Summit Ignition Box

Interesting. Looks like a better design than the fake transistor ones. A lot may depend on how well they heat sink the transistor. Can’t really tell from the pictures.

When looking at something like this, keep in mind that a lot has changed in the world of semiconductors since the 70s. Most of the heat in a power transistor is generated during switching. Since the speed of semiconductors has increased dramatically in 50 years, the switching time is much less and thus less heat is generated. If you generate less heat, the parts can be smaller.