I know the sealed cartridge bearings are easier to install, may last longer without upkeep and such but they are also twice as expensive at minimum. I'm converting to threadless and see that loose ball bearing headsets can be had for under $20. My threaded loose ball has lasted fine, even without maintenance.
Any reason to avoid these? I'm updating a C&V bike with carbon fork and threadless stem and am on a budget. maybe I can upgrade when it wears out.