I've seen that reactor for sale on several websites throughout the years and have always wondered about it's effectiveness. With the amount of gph from the mag drive I doubt there will be any form of c02 buildup at the top of the reactor, a problem I have encountered if you have a lack of flow going through the unit.
I have tried multiple reactors, DIY, and atomic inline diffusion. None of which have worked very well with my eheims low flow. For now my ceramic diffusor is giving me superior results.