Amen to that! Do these work as well with other similarly sized speakers that are 11" or less across the bottom front? What will you hear that is better?
Yes these will work with other speakers. Below is a drawing with the specs. You can see that the slots for mounting allow for different speakers bolt patterns.
As to the sonics, I have not had a chance to directly evaluate that as yet, plus these type of additions depend on many factors. In general I have found that good spikes etc will improve bass definition and overall imaging, usually with a greater sense of clarity and "space" around the notes.