All four solutions work.

WinBind is the hardest to configure. But it integrates well with the rest of the system. And it is well documented.

Likewise works out-of-the-box, but is hard to grok. Some things (like listing users) work faster. But it brings in a registry. And it is ill-documented. Whatever can be found on the Web is for the Enterprise version, is (therefore?) inconsistent with the installed software, and most is of the type: "the on/off button is to turn the gibberator on or off, use only when many flipcount must be set".

Centrify is also very easy to install. Its documentation is better than Likewise's. But system-wide configuration files are <horrors>overwritten</horrors> when the Centrify package is installed.

Having spent some time on figuring it out, I like the fourth option the best.