Comfort and build
The foams are no doubt extremely comfortable. In order to wear it properly, user will need to squeeze the foam to a smaller size before it is being inserted into the ear canal. The foam will slowly expand to fill up the canal space. It doesn't really isolate much noise compared to the original Shure Olive tips. The Hippo foam is must more lighter though. As for the build, it is a bit more fragile as I had thought, for those who wanted to use these foam, I do not recommend to keep detach these tips as the foam will easily tear off (especially on Shure's IEM).
There are ups and downs that I had noticed after I used these foams for 3 days of listening. One drastic change that can be noticed is the bass is tighten quite a lot and the amount of bass coloration in SE215 is decreased. Next, the soundstage, is very much widens and deepens it has a rounder and more complete soundstage as before. One of the downs is that the mid highs is rather slightly harsher than before. I tested on a CD Chinese song by an artist called Fish Leong and noticed the sibilance is much more obvious than before. I did a test on "Salvatore Accardo plays La Campanella by Paganini" and noticed the triangle in the music is weaken and the decay is shorter.
These foams overall does improve certain part of the Shure SE215 signature. However, there are still some aspect that buyers might want to consider about if they are using Shure SE215 as the changes might not suit everyone. But considering if these foam does improve your IEM signature and you love it, it will be a great buy.