KS1 is a V shaped set, very good for the cost of sub $20 (ie skip a restaurant meal for it). Good timbre and tonality, bottlenecked at technicalities.
I think it is a good beginner set for those new to the hobby or perhaps aa a gift. But experienced chifi connoisseurs and those that own higher end gear will definitely have heard something better.
Pros
Well fitting, light, comfortable.
Above average isolation.
Good organic and analoguish timbre.
Laid back tuning, smooth and non offensive.
No sibilance, safe treble.
Easy to drive.
Cons
Bass bleeds, not the most textured bass.
Intended V shaped tuning, not for mid or vocal lovers.
Technicalities below average.
I haven't heard the KBEAR F1 but a few folks here like
@Slater who owns them says there are three to four different F1 versions incorporating different drivers. As such I think it would be hard for others to advise too as the different driver versions all sound different. Perhaps some don't even know which version they got in the mail.