should I get an Amundsen SatNav?

Hi, apologies if this has already been discussed elsewhere, but I couldn't find it.

I'm new to Skoda, intending to buy a new Fabia Estate, and trying to decide on the spec. In particular, whether it is worth paying an extra £500-odd for a factory-supplied SatNav.

I do currently have a portable TomTom, which is an excellent SatNav. However, the wires are a nuisance, and the fitting of the wires into the machine wears over time so that it needs the body replaced. Furthermore, it's a faff to hide the TomTom out of sight when I park somewhere dodgy. So I would much prefer a SatNav built in to the car.

I have a few worries from what I read about the Amundsen, which is I believe the only factory-fitted option for a Fabia?

1) can I specify a destination using latitude and longitude? My sporting interests take me to a fair few fields in the middle of nowhere, for which postcode would be little use (even if it could be input). A road name is not always easy to find.

2) can I add my own points of interest? It's handy to record cafes, teashops, pubs etc which I have liked and might want to go back to.

3) how easy/expensive is it to get the maps updated?

Any advice much appreciated.