Yes, I used 'Palas' as a base template for my company's site. Support is in general good, I'd say: lots of elements are worked out so you can build your layout with building blocks very rapidly, and configurability is often high. You still need to do work if you want to have your site look like something unique, but in general these templates are a great way to start.

And they are the same thing, templates from bootstrap or from 3rd parties: you get an example site with several pages, pages with building blocks on them, less based customization css on top of bootstrap, documentation which block does what so it's easy to find where to customize e.g. a header color / font.

You do run into messy ones that you basically have to repair before you use, but those themes are often very high quality under the hood.