Beautiful car seat, though not sure about the fabric
I have had 5 Clek Fllos (so obviously am a fan), with 3 different seat material. The material of the Special Edition Paul Frank was like felt. The material from a 2016 Fllo (Ink) and a 2017 Fllo (Flamingo) was a slightly nubby material, which is hard to describe, perhaps like a boiled wool. The 2017 Thunder is a somewhat slick material, like a scotch-guarded ski jacket or a high quality shower curtain. I'm guessing the Thunder may be a bit easier to keep clean (though I haven't had to clean it yet), and the material doesn't make a tremendous amount of difference to my daughters since they typically have pants and long sleeves. I love the color and pattern of the Thunder, though.
ProsExcellent safety construction
Able to install 3 in a row, or two with one seat in the middle position
Easy to get a secure fit with the straps
ConsStrap release button is a little more recessed than I would prefer
LATCH installation is a little less intuitive than other seats (though I prefer using the seat belt anyway)