I switched this blog over to the Isso commenting system from Disqus, and added support for Isso to my popular Jekyll theme jekyll-clean. It was always a bit of a battle getting Disqus to work right - I had quite a few comments that would not show up, and just logging into Disqus doesn’t work right if you use privacy blockers like I do (Privacy Badger, Ublock Origin, and HTTPS Everywhere for those interested - these are all worthwhile browser extensions to use). There were always some questions about what Disqus does with data, as well.
Isso is self-hosted, which means you can’t directly use it on static webhosting such as github pages, and while your data is arguably no more safe on someone’s random self-hosted blog (such as this one!), Isso allows anonymous comments - so people only have to provide as much detail as they wish. For people who want to demand it, you can make the email and name fields mandatory, but there’s no verification so in practice there’s not much point (when I come across comment forms that require an email I always give a fake one).
We’ll see if spam is an issue - Isso has a basic moderation system. That’s one benefit of hosted solutions such as Disqus - they have a shared knowledge about spammers and can make some reasonable attempts to control it, along with requiring you create account (with the obvious downside being the lack of anonymous comments I mention above).
So, in the end, it’s not a clear choice so everyone has to choose what matters most to them - there are a few other options other than Isso as well, but I liked the fact that Isso is small and simple, written in Python, and uses sqlite for storage. There’s not much to go wrong nor much attack surface for abuse.
Integrating Isso with Jekyll is pretty easy, you can take a look at jekyll-clean to see how I approached it.
On the topic of Jekyll for blogs - I switched over to Jekyll for this blog about 1+1/2 years ago and don’t regret it for a moment. It’s simple, easy to modify and theme, and super super fast.