What's the difference between the signature and legacy series?
The signature series are selected projects that meet certain criteria. The drivers are all currently available, of high quality and consistency, personally evaluated by me for distortion as well as frequency response suitability. The designs are felt to be of widespread usefulness to the diy community. Extensive testing, prototyping, modeling and multiple iterative measurements are used. The final product has to built, listened to, and had positive feedback before it gets listed here.
The legacy series are all good designs, however, lack one of the above criteria. In the case of the Mini, the drivers are not commonly available. The Usher HT is a very specialized unit, a 7" in the smallest possible cabinet. This compromise leads to a pronounced baffle signature and an FR that isn't up to the highest standards, though it excels for HT. (Basically this is a B*se cube on steriod!) The RS22528A is almost a signature series. The problem is that I have not built/heard/voiced the updated version with the nonferro RS28A. The folks who have built this think it's excellent. However, I have not personally heard/verified it. So, it gets bumped down a notch.