I followed the instructions carefully by spending nearly two hours checking all settings and configurations.
Sadly it behaved poorly for me, perhaps because of the template I am using (YooTheme) or simply there is a bug somewhere - btw I am not a Joomla newbie and had installed other extensions without any trouble in the past.
I admit the instructions was a little too long, however it is probably because of the numerous feature requests from other users, so likely not the developers fault. And as a freebie I did not expect too much. Instead I am now looking at a commercial version with a smoother and easier installation process.
Being licensed (and being free) exactly like Joomla! core is, yvComment has commercial support just the same way. Moreover, the GPL gives you as a Customer much more flexibility in selecting the source of support (comparing to support of commercial products/extensions).
In your case the support may come from a Web designer in general and from developers of the template that you are using (YooTheme) in particular.
Good luck, gavman, and thank you for the review!