[syslog-ng]Differences between 1.5.x and 1.4.x

How stable is the 1.5.x series of syslog-ng release, and is the only difference that 1.5.x is a development tree? Are their significant configuration file differences? Where would I find information on variations and additional features within 1.5.x series? Thanks for all the help Brian Seppanen seppy@chartermi.net 906-228-4226 ext 23