Also, if you look at the release notes for both of them I think it's fairly easy to see that Gitea is developing at a much faster rate and has more features than Gogs already with a lot of nice features coming in 1.5.
However, I'm fairly biased, I used Gogs for a long time but switched as soon as Gitea popped up for the reasons above. Since then I've contributed a few fixes and features to Gitea as well.
- Issue due dates (https://github.com/go-gitea/gitea/pull/3794)
- Approval/comments on pull requests (https://github.com/go-gitea/gitea/pull/3748)
- Multiple assignees on issues (https://github.com/go-gitea/gitea/pull/3705)
- Dependencies for issues (https://github.com/go-gitea/gitea/pull/2531)
- CI status on pull requests (https://github.com/go-gitea/gitea/pull/2519)
Long story short: Gogs was slow in committing pull requests. The maintainer says it's because he has specific standards, the community sees it as just slowness. Anyway Gogs was forked into a new version that is supposed to be more active and well maintained.
Well the forking lit a fire under the ass of the Gogs maintainer and he has since become much more active than he was. For a month there there was reason to switch to Gitea as it was adding features that Gogs did not have at a rapid pace, but Gogs is now mostly caught up and there is reason to prefer it. I personally would go with Gogs. 1 passionate person > design by committee of people with shared low responsibility.
From gogs to gitea all metadata has been taken over (db was identical then). -- For gitea to gogs I read that the two projects have diverted. As I could afford to loose metadata of my not too many projects, I went back to gogs ditching and recreating everything (wrong switching decisions should be punished, don't they;).
If you're comfortable with Gogs you can stay though I do recommend to try out Gitea. IIRC from last time I compared, other than a few minor features they are mostly on part with Gogs.
The comments on that post suggest that Gitea is more actively developed, at least shortly after the fork, but I haven't checked to see if that's still the case.