Yes, Lektor is great. The outstanding features are the admin interface which allows even non-technical people to create and edit content, and the content models which allow to work nicely with structured data.

For example, in the past I have built a multilingual media database with Lektor, where items could be, say, books or movies, and depending on the content type I could enter a "number of pages" (int) or "duration" (time) or "author" (selection from a list of "person"-typed contents), and the admin interface would be auto-generated. I haven't seen a similar functionality in other SSGs.

Downside: For large sites rebuilding takes very, very long...