Auralex SubDude HD - Subwoofer Isolation Platform

Has anyone tried the Auralex SubDude(HD) Subwoofer Isolation Platform underneath their subwoofer?

If so, was it worth it?
Yes. Works great and also protects floors and the sub. Inexpensive as far as tweaks go.
Mine works fine to decouple and eliminate spurious vibrations from being conducted through sprung flooring. However I am curious to try a more sophisticated coupling approach such as Sistrum platform. This should theoretically provide a drain for vibration that is otherwise broadcast from the walls of the speaker cabinet, possibly improving focus.
I use two of the smaller SubDude platforms under the speaker stands for my speakers. I don't believe that they improve the sound. They do, however, prevent sound from penetrating the floorboards and disturbing my downstairs neighbors.
What are the dimensions of the smaller platforms? I have looked around and can only find the 15x15 and those are much too large for the small floor standing speakers for which I would use the platforms.
I bought a bigger Auralex platform, then I just used a circular saw to cut it to size.
I use the Auralex SubDude HD for the subs in my 2.2 channel majority music system and an Auralex Great Gramma for my HT Sub and they have really helped. More so in the HT system I heard improvements with the bass.

Has anyone used Auralex SubDude platforms under tower speakers ? How did they influence/change the sound or were there any benefits at all? Thanks in advance.
Thanks for this post as I'm in the process of getting a pair of subs. Can anyone tell me the real difference between the SubDude and Gramma? I understand one is for sub and the other more for monitors but on their website there is a review link on the Gramma where the reviewer uses the Gramma for his sub:

The review is old 2004, so may be they didn't have the SubDude back then. My subs have foot print of 17.25" square so the bigger Gramma will fit better, if both attenuate the same frequencies.
Auralex seems to have changed the SubDudes. I've had a large rather industrial looking one under my Velodyne HGS-15 for several years, and I recently added a pair of the new smaller (in slick black velvet) under my KEF Reference 104.2s, replacing spiked planks.

Of course with the sub, the SubDude eliminated boom and extended the LF response as expected. With the mains, the SubDudes cleaned up what I think may have been a bit of resonance-related overhand that was most noticeable with massed strings, especially those so common in Beethoven symphonies. The big surprise, though, was the improved imaging and greater depth of soundstage.