Very noticable difference to sound when using these, they do everything you want them to do for decoupling, being able to angle them was also a benefit, they are very expensive but as stated, when compared to foam, there is no competition, it was a worthwhile investment for sure. I went for the 200's as that was the size recommended by isoacoustics for my monitors (Kali LP-6), i'm pleased i did not go for the smaller, cheaper version because they function so well and in the future will be suitable for larger monitors also. In short, if you are serious about sound, it's worth investing.