They are much different in terms of feel. The material is kind of sticky in the hand, but not really in the ear. I find for me (with other iems) I get a better seal with them because they kind of deform better to my ear, while the normal sednas are just too stiff. They market them as a different material that reacts to body heat to kind of take the shape of your ear, which they seem to do, then return to normal at room temp. My early impressions with them are they they kind of "vanish" in your ear once they sort of settle. Overall a positive experience I think. And definitely unique because they are a totally different material.
Not going to talk too much about sound, because for my purposes they sit low enough down on the stems of the iems I have used them with so far that they just dont obstruct the sound at all. But, the seal they make does seem like its quite good, so for that purpose, I would say its a good thing.
But... they are dust magnets and I find myself wondering how exactly I will be able to wipe them down properly without getting like a wet cloth every time. And they are really really stupidly expensive for tips, to the tune of $30 US for 2 pairs.