General Deployment releases are considered to be stable and are supposed to be quite mature (based on download stats).
General Availability Versions are considered to be stable but are quite new and have not yet been deployed widely enough (based on download stats)
All bug fixes and enhancements will be first released as a general availability release and moved to a General Deployment release once a particular version is stable enough.
If you want to play with the latest and the greatest features then download one of a daily snapshot releases which are made once a week From time to time... one of these snapshots will be released as a GA Release.