In my experience, audio is one of the bigest Marmite topics.
I had the previous Zenec MC2000 for over three years and thought it was good - certainly good spec for the money compared to what was available at the time.
The NC2010 is miles ahead of that one - much slicker, better sound options and the GPS is great. I've, ahem, modded it to take newer software and also very recent maps and it seems very slick. So much so that I will no longer use my up-to-date TomTom.
Instructions come up on highline display etc and use TTS - can't see why the guy would complain as IGo is fairly adaptable once you get into the guts of it?
I haven't really used the Bluetooth yet but it's Parrot and supposed to be superior to the old unit - which was great and still is (in my wife's car now).
I know some people have had faults develop but I'm hoping that was very early models. A new software version came out recently (11.0) you can get it from zenec.de and put it on a USB stick to update.
As for the install, if they take more than an hour to do it they're taking too long (including routing GPS/TMC/USB dock).