My two cents.
I have lead and sand filled stands that used to be on spikes. I wanted a nice looking solution to replace the spikes and bought the Gaia 3's. I didn't expect any change in sound because of the weight already in the stands. There was a change though and for the better.
I guess on a timber floor any bass that makes the floor vibrate will have an impact on the accuracy of the tweeter if that vibration makes its way back into the stands and therefore the speakers. No matter how well the tweeter is isolated from vibration from the box itself, if the whole stand and box move, the tweeter will move along with it causing distortion.
Of course you can use Bunnigs's pads and they may well work really well. Where the Gaias pull ahead are looks (the reason I bought them) and the fact that they've been tested to work under a specific load. A pad made to take the weight of a washing machine is't going to do much for a pair of bookshelf speakers because they would be too hard. Put a pair of Gaia 3's under your washing machine and they will simply get squashed and possibly even end up metal to metal.
As for the Apertas, A guy came into the store to pick up some Gaias to replace his Apertas. He later sent an email saying he was happy with the improvement. Not my words but worth considering.
@satanica As for measurements; The improvement is large enough to not need measurements to prove there is an improvement. You don't put a Volt meter on your kitchen light to check whether it's on or not. Your eyes will tell you. The same goes for isolation. Whether it needs to cost as much as the Gaias to get the desired effect is a matter for everyone individually.
To put the improvement into perspective; it's not as big as room treatment, speaker and chair placement but once you have all those sorted, the sound gets more relaxed in the highs. I did not notice improvements in the bass but I have relatively small speakers in a large room so bass level is already an issue.
Hope that makes thing a bit clearer for everyone.