Just in the middle of trying to make it work with eZ Publish 4.1.3 and eZFind 2.0, so far no success on my dev machine, however it seems to work fine on another... Plus, eZFind search as such does work fine...
I did dig into the code a little bit, there seems to be a problem with oid query type, but that's it...
Ok, got it running. Nothing special was necessary, the node query type works fine for me. I guess my problem was that I wasn't paying attention to the result array which provides much detail on how the query went, for example tells whether there was an error or not and also distinguishes between empty searchResult and invalid searchResult. The reason I didn't get the results was possibly related to very little content and heuristic method used.
Anyway, seems to be working fine.
Now working on thesaurus and flection integration ;)