Squirrly SEO shows you Google Analytics Data in sections of the plugin where you can actually take action to improve those metrics.
For example, in the Focus Pages section, Squirrly shows you Traffic data, Bounce Rate data, and Time on Page data for a specific page you set as Focus Page.
(more details about Focus Pages here)
Squirrly also shows you which pages are bringing the most traffic to your site in the Audit.
(more details about the Audit here)
Squirrly lets you monitor your rankings and shows you the best ranking for each keyword as well as organic clicks, impressions, and social shares.
(more details about this here)
What Keyword Hero is doing is a very different kind of keyword tool, because it doesn’t involve research for new keywords.
It involves traffic analysis and figuring out which existing search queries drove traffic. It looks similar to what you get when you click to Sync your Google Search Console keywords to Squirrly SEO, except that Keyword Hero can (most probably through big data) identify other keywords that you were found by, which don’t normally exist inside GSC and Google Analytics.
Keyword Hero doesn’t offer an SEO Live Assistant for on-page content optimization, a Keyword Research feature, or a Website Audit feature like Squirrly does.
Therefore, Squirrly SEO could be a better fit for people looking for a solution to help with a broader range of SEO activities.
You can see over 500 features that Squirrly offers here.