I saw a KF the other day. I asked the mom if I could peek at her seat as I hadn't seen one yet.
And let me tell you, it's
is beautiful. It really is everything we rave about. Tiny chest clip, lovely newborn insert, it's lightweight, the handle is comfy in your hand, the fabric was nice, and the seatback is quite tall (though not tall enough to accomodate the 30lb limit of the US's KF30 I don't think).
Mom talked about how easy the base was to install, and that it's by far the easiest seat to use she's ever owned. Her baby was about 8wks and just over 12lbs. I reminded her to remove the infant insert when she got home (it's used from 4-11lbs only IIRC), and she told me thank you.
All in all it was a nice converation, and such a nice seat to "meet" (lol, canmom).
ITA it would be a major toss up for me... the KF for it's 'perks' or the SS1 for it's practicality... I have micro babies so it'd probably be the KF.