However, since they are all third-party solutions, there are such varying levels of complexity and support I think you would prefer to use the built-in versions

However, since they are all third-party solutions, there are such varying levels of complexity and support I think you would prefer to use the built-in versions of replication. Depends on what you need replication to do for you. If you just want a full replica of your db, the built-in stuff is getting really good with 9.x (as far as I've heard; I have no direct experience with it). That said, the PostgreSQL hackers are specifically making most-case tools, and for most people, they're great. If you have more complicated needs, though, you'll need to look elsewhere. The built-in tools are all-or-nothing, and single-master. I've worked in multiple environments where we had needs that went beyond what they'd have offered, had they existed at the time; multi-master, replicating a subset of your database(s), and transforming the data in-flight during replication are real needs that organizations find themselves facing, and based on what the core committee has said about their plans, those aren't going to be addressed with the built-in tools any time soon, if ever.