It works well. I think you can find HTML format docs too. I'm one of the authors of the Java JDBC driver thats going to be in the PostgreSQL V6.2 release. As I've been lurking here keeping track of what's happening with TASS, I'm offering to help anyone who has problems with PostgreSQL inrespect to setting up under Linux, or accessing from Java. Also, I'm working on a Java application to access postgres which should be available during the next week.
Speed is quite good.