I’ve been using Stackbit for a few months now, and had created around 10-20 sites using it (I lost count). I even started a productized service around this offering, because it was exciting enough when I first tried it! But few months on, flaws begin to emerge. So here’s a sum up of the pros and cons:

Pros

• A website in minutes! I used to use Wordpress, and even Wordpress isn’t that fast to set up. 
• Great design. Pretty sleek designs from a good selection of templates.
• No coding required. Just like Wordpress, Stackbit is also like nocode for JAMstack. Just click click click, and you’re done. Editing content can be done via a CMS too.
• FREE web hosting on Netlify. That saves you anywhere from the cost of a good meal out to a few hundred bucks per year. 
• Super-duper fast to browse. Stackbit makes static websites, and uploads it to a global content delivery network. That means it loads much faster than say your average Wordpress/Wix sites.
• Vault-like security. Because it is a static site, there’s no very very little vulnerability to exploit. So, no worries about hacks. Or updating your site.
• Great for MVPs. The speed to market means you can test ideas and put out a landing page for your SaaS or product in minutes. 
• On-page WYSIWYG editing. This is a new feature. It used to be a con when they didn’t have it, but now with inline editing and instant preview, makes design and editing much easier.
• Small, emerging ecosystem of documentation, content, plugin and themes means there’s potential opportunity to fill in the gaps. (Also a con - see below)

Cons

• No analytics. No easy way to inject Google Analytics into the site, unless you code. 
• Connecting a custom domain - no coding required to connect a custom domain, especially if you do it via Netlify. But can be improved, as it can get intimidating for a nocoder.
• No meta tags and SEO optimisation. Again, unless you code, there’s no drag and drop way to add the important open graph images to make your website look great when shared on social media. Meta tags for custom pages - even harder. I’m still trying to figure it out. Even adding a favicon needs you to code. What’s annoying is this is pretty basic stuff that all websites need!
• It’s either super easy, or it’s super hard. Yes, a website in minutes, but once you need to customise it somewhat, you’ll need to learn React, Node, command line, etc.
• Tiny ecosystem of support, plugins and themes, unlike Wordpress (which, in my view, it’s impossible to beat as far as ecosystem size of nocode tools go). Netlify Build Plugins and Gatsby plugins help, but are fiddly with code. Good documentation and third party content/blog articles about JAMstack are still limited at best. 
• Build times are slooow. I use Gatsby for static site generation, and average of 45s-1min for every tiny change you make. What you save on load times for your user, is dumped onto build times while you edit the site. 

Overall

Great use case if you just want a sleek website up quickly, and don’t need to fiddle with it much. Awesome for ‘set and forget’ situation. 

But once you want to customize things, it’s likely harder than Wordpress or Wix, especially if you don’t code.