Finally after a few days of testing I have something to share:

For all that have voice command error message - see post #212.
Solution = download files recommended in post #47 for CNE or in post #221 for CNNA users and uncompress them. Copy all files to your nuvi (*.asr to .system/ASR,, *.sid to .system/SID and *.db to .system/SQLite). Reboot, connect to pc and launch webupdater to verify if you need any new files for your nuvi to work the way you want. Enjoy!

I have one question: is there any thread where we can only read and post things related to the 37xx and 34xx user interfaces? Or is it ok if it can be done here?