One of the interesting things about Prusa’s FDM 3D printers is the availability of official upgrade kits, which allow you to combine bits off an older machine with those of the target machine…
It depends a bit on your needs. I’ve upgraded mine mainly due to space concerns - it is quite a bit smaller than the mk4s with enclosure. As a positive side effect I can now print large PC models without warping - something that never worked properly even in an enclosed mk4s, probably due to the larger enclosure volume.
I’m not convinced the Core One is a better machine than the MK4S.
It depends a bit on your needs. I’ve upgraded mine mainly due to space concerns - it is quite a bit smaller than the mk4s with enclosure. As a positive side effect I can now print large PC models without warping - something that never worked properly even in an enclosed mk4s, probably due to the larger enclosure volume.