Been lucky enough to use Gamma for a few months, and I find it pretty pleasant to use. I don't see anyone comparing it to Tome yet, so here's my $0.02: they're very similar, but Gamma is much farther along in development - many more block types and you can actually move them around and position them in a very intuitive Notion-y way.
I've used a lot of tools in this space now that I think about it, thanks to Product Hunt. Gamma definitely has carved out a definite niche in my workflow. Today I mostly use beautiful.ai for large meetings (like company all-hands) or pitch decks, Notion for detailed documentation, and Gamma for stuff in between (e.g. smaller team meetings, quarterly planning, and so on).
It's great for preparing presentations and a quick porfolio but the part where you create a website could be improved (maybe a landing page with multi-page content, a little bit control over on-the-fly creation where you interfere with the AI and modify at that instant). Great tool overeall!
This is good stuff. I use it mainly to create a strawman deck that I'll use to fill in the content. Bonus - throws in the occasional good data point as long as you prompt the right question.