I tried the Marigo dots to "tune" my two 6' by 8' windows, which is the "back wall" to my living room / listening area and they actually had an audible, positive impact.
My Summits are about 5' (to the panel) from the back wall. Other equipment includes a Classe Audio CA150 amp, a CJ Premier 18 LS preamp, a Theta Miles CD player, a Michael Green clamp rack, and Mapleshade interconnects and speaker wire.
To make sure there was something to be heard, I had a non-audiophile type friend with me to do the before / after test. I told him nothing regarding what these dots might do. Used high quality male / female vocalist type CD's as the reference. Had my friend listen to 3 selections (approx. 2 minutes per selection) and then I repeated the same, with different material that I'm familiar with, myself. We then installed the dots (2 - 60mm dots per window corner / 16 total) and listened again.
My friend said that he thought the volume should be backed off by 1 to 2 DB with the dots in place. He also noticed the higher frequencies having more depth with additional clarity.
My initial gut, confirmed after more listening, is that the entire presentation had more uniform "punch" that was non frequency dependant. Better soundstaging, dimensionality, and overall clarity. And it was not subtle after listening to a variety of material. Same difference with rock, classical and jazz.
Don't know what to say other than I'm keeping them. Given the "voodo" nature of the puppies, they were shipped to me with a money back guarantee thanks to John at the Cable Company. The apparent theory is that they "retune" the resonant frequency of the glass. Beats me but I'm totally convinced of their efficacy.
Moral of the story. If your looking for room treatment but don't want to sacrifice room aesthetics, you should try these out.
PS: Bottom line is that the overall musical presentation is much more engaging.