We have (almost) always had a nightly build zip file users could download and try out, but it had a couple of issues if users mixed GA/Beta releases with nightly builds.
Bleeding edge users were also complaining that they had to manually unzip the nightly builds instead of just having an update site to go to and get the latest builds.
We keep both a trunk and a
latest branch update site so anyone can now more easily help and see their favorite feature implemented or bug resolved in the proper build.
With the nightly build updatesite you can try out the latest build, report issues in jira and when the jira get resolved wait for the next build to arrive and update your eclipse to see how/if your issue got solved.