Infinitely more comfortable and better-sealing than the stock tips on my Shuoer S12s, with excellent sound quality. They're not incredibly grippy, though, and they tend to move around a bit when they get sweaty. Also, they needed to be stretched quite a lot in order to fit onto the S12's nozzle. Maybe these things are normal.
This review is based on using the CP100+ on the Shure SE846. You will need the adapters before these fit the small nozzle of the Shures but they fit tight and work extremely well. According to SpinFit the CP100+ has a little more defined highs than the standard CP100. I can't speak to that since I have never tried the CO100 but I can say that on the Shure SE846, which has a slight rolloff starting around 10K, the highs do pop a little more than with other earths that I tried. They honestly made more of a difference than I expected. I notice it mostly in percussion like cymbals and snare but also in acoustic guitar like Eric Clapton's unplugged version of Layla, Eagles Hotel California or Poison's Every Rose Has Its Thorn. The lows are still deep and tight without getting muddy and bass heavy. Vocals are crisp and clear. Soundstage is wide and clear especially on track with Dolby Atmos. Sound isolation is good but not great if you are in noisy environments. Comfort is as good as I have found. I can wear them for hours without ear fatigue. I have owned SE846s for about 5 or 6 years now and have been on a constant search for the ones that are "just right". The CP100+ are as close as I have come. They are my new favorites.
SpinFit CP100+ | Premium Eartips (2 Pairs)