Jon Brodkin, writing for Ars Technica:
Unfortunately, it’s kind of a mess. iCloud Keychain does accomplish the most basic things you’d expect a password manager to do, but it often does so in an awkward manner. Important functionality is hard enough to find that it may be effectively hidden from the average user, particularly on iPhones and iPads.
Ultimately, iCloud Keychain can be put to good use if you’ve carefully examined what it does well and doesn’t do well. It works best as a complement to a complete service like 1Password or LastPass, but it just isn’t convenient and robust enough to act as a standalone password manager.
I think it’s a bit harsh to call it a “mess”, but Brodkin provides a good overview of what iCloud Keychain does. Complaining that it’s not as full-featured as 1Password is like complaining that iPhoto doesn’t do everything Lightroom or Aperture do.
Comparing iCloud Keychain and Lightroom is a bit odd. One helps to manage the security of one’s online life and is meant to resolve a security problem for anyone who uses the Web. Lightroom is a specialist product that caters to experts in a particular field. The two products may have an overlapping user base (i.e. individuals who want secured usernames and passwords) but otherwise bear little resemblance to one another.