Thanks!I can only answer as far as my personal experience but it's much more comfortable than the Groovy tips. The fit is significantly better for me. If you're familiar with the rotating sytem and high grade silicon of the SpinFits, you get what I mean and the difference to regular tips
I simply forget the i4 even for extended time e.g several hours, and this alone would already be enough for me to recommend them as you totally forget the i4 and the listening experience is simply awesome.
Sonically, there is a marginal improvement to the groovy tips I would say a tad better bass compared to groovy not sealing (for me) although I don't believe fit is really changing the sound that much compared to usual IEMs after all those 30mm planar drivers don't require a seal to give you great bass Still I find it does make a difference, and it's a more familiar sensation for those used to have a seal on their IEM. Groovy and included tips always felt like they floated in my ear not matter what size... I think it's a matter of silicon grade (their hurt my ears pretty quickly too) and maybe shape.
Sound change is much more apparent when I tried the T-600 complys (the most bass, not night and day still) but comfort is not as good as the SpinFits CP155.
I also find the comply tips uncomfortable.