This review is four months after the installation of an active depressurization system, and it's still working just great. Radon levels are around 13 Bq/m3 on average, and sometimes down to 3, and fell to this level within 36 hours of installation.
Colin was amazing on the day of, taking the time to answer my many questions and explain the science of how it all worked. He even took the time to demonstrate how little air pressure is involved in bringing radon into your house.
The work was quickly and cleanly done, and the place was spotless after, even having to drill an exit pipe through the house concrete in heavy snow. I don't want to get high radon ever again, but I do hope to work with Radon West in the future.