The satnav works like a standard Garmin satnav - having the satnav built-in is great, GPS reception is fine and it works well. The GUI is a little blocky and looks retro. TMC is extremely flaky and doesn't work at all for me around Cambridgeshire - the TMC antenna is a cable that runs around the top of the door so I have sourced an FM splitter from the manufacturer Kenwood which I will fit when I get a chance.
If you don't need it to look OEM and built-in, a standalone satnav will be better value and you can take it with you.
The other consideration is that the unit is installed by VW dealers behind the glove box unit so if you wanted to access the SD card reader to update maps or POIs, you would need to take off the appropriate trim and take the whole glove box unit out. I have run an SD card extender from mine down into the glove box so perhaps ask the dealer to do that for you or see if there is a better install location. While I had access, I also took the opportunity to plug my laptop into the satnav and add some extra vehicle icons - who doesn't want Super Mario rather than the default red arrow??