I'm trying hard not to get too excited because I know it can turn anytime.
...ditto, though the site-wide nature of the upgrade gives a feeling of stability or at least... "i know Google was wrong in the first place" and things can turn back again.
So what did you do, and what did you not do that you felt that you should do. The analysis would provide helpful insight.
Google's aversion to Directories has been reasonably well documented, so we hived off our entire classic country-city drilldown directory into a new domain with 301 re-directs.(this, even though the bounce rate / time spent on page of the directory section roughly mirrored the stats of the rest of the site). Retained the search directory box, so that user experience was not affected. Used a whole lot of no-index to those pages that were having a combination of high bounce rate / low conversions & low value (including less time spent on page) in our opinion as I didn't see much downside in doing that. Didn't make changes to our good content pages even though they were badly affected, because I simply believed Google was wrong on that one.