It's ALWAYS the best option to keep your CMS and addons up to date.

Both the Core team and Addon developers spend countless hours refactoring code & making improvements.

These improvements are not just there because it sounded fun (for the most part anyway). They are there to address performance issues, security issues, and then also to add new features that improve the quality of the end user experience as well as the developer.

If you have a site that is a "hackathon" , you should do the following to move forward:

1) make sure ALL modifications are root level overrides. i.e. - custom block views, single_pages, and page_types. This is so that any addons updated, you do not lose code/work

2) copy your server to a test environment.

3) update your test box and notate any and all issues, and what the solution is/was. This likely will include minor corrections to your overrides based on the new versions of addons and core files.

4) now knowing what to expect, implement on your live site. You shouldn't have to much down time if performed in this way, and you know what to expect and what the fix is.

I can't stress enough - although painful if the site is a real hackathon - it is imperative to keep your stuff up to date.

ChadStrat