I found out that [block name='my-block'], as it it is written in the documentation, does not work (RuntimeException), but [block name="my-block"] works, and also [block name=my-block]. Should be corrected in the documentation.
By the way, Flextype looks quite promising, I am just testing it, and I like it so far. In my opinion, it should be kept small. For me, it is fine that there is no admin backend, but I think that my clients would not be able to handle a CMS this way. An admin area as a plugin (not in the core) could be the most acceptable way.