So now I have had a chance to really listen to the isolated networks. I also switched back to placing them on the floor for a few days and then returned them back to the Vibraplanes. The difference is interesting. Up on the isolation, the sound is a bit more focused and clean. Details and dynamics are slightly more clear and violins and piano sound more like what I hear at the symphony. But it also reveals better the flaws in less than great recordings. On the floor, the bass seems warmer and slightly bigger or "fatter". There is a bit more color and euphonic character to the sound which is extremely pleasant, but it is a bit slower and I think slightly less accurate. It is also a more forgiving sound. Both ways sound very good, and if I did not hear both, I would not know the difference and could easily live with either.
I have little experience with tubes in my system, though I have heard plenty of other systems with tubes. The difference I hear when the network boxes are not isolated and sitting on the floor is similar to the way people describe adding a tubed component into the system chain. "It adds just the right amount of warmth, body and midrange bloom. It is so smooth and lovely sounding. Very musical and less analytical, etc. etc." I don't want to debate tubes vs SS, but that should help describe the differences I hear.
I am biased toward a cleaner, more accurate sound, so for the time being, I will leave the networks up on the Vibraplanes. But I can see wanting to try them on the floor again in the future for a slightly different sound.
I wonder if you will be able to 'chase down' if there is something else in the system (with the isolation on for your network boxes) that may alleviate some of the hard ride of your analytical character. It may very well be that the music itself is hard...the rest of your system may well be mellifluous.
The only reason I say this is because when I placed my Gryphon amp up on an Auralex isolation platform, I got a lot more space in between my notes, and the soundstage pushed back several feet...I loved that. I knew my floor was 'terrible' for vibration. But the treble hardened and it really really irritated me to have to have some benefit and also to go backwards elsewhere. Then, when I damped the top of the Gryphon with an Artesania damper and about 20kg of brass weights...so the amp was basically in an 'isolation sandwich' the sweetness and purity of tone not only returned...it was purer without the 'noise' from my floor. so clearly the initial experiment (for me) was worth doing as it led to the ensuing 'chase' to find where the other bits of improvement lay.