When I picked up Slippers, my 8520 was set up by the salesman for me.
I've not had any problems at all with it in the 6 months I've had my 500.
Admittedly only use my phonebook side though so can't comment on the text reading/displaying. Yes the voice recognition doesn't recognise but then again voice recognition tech isn't "there" yet.
Our salesman was a dab-hand with linking the 8520, true it took a repeat of a few stages which hadn't been recognised the first time, but it took less than five minutes for them to do overall.
If persistent issues, and the manual/link already suggested isn't working, try calling your local dealership first -ask for their advice. If they're quiet they probably wouldn't mind showing you how or doing it for you - good to know if it's just a lack of knack rather than a fault. Hopefully yours is local but if not ask if there's someone there who's good with this and ask if they would mind talking you through it. Hope you're sorted soon.