Wouldn't bother tbh. I use Google maps on my phone and I have the HDD version.
If you do have to use it, it'll get you there...eventually. But Google maps/waze is always receiving live data, and will reroute if needed.
Far superior.
There are also options to swap the head unit out for an Android unit, which again would be far superior. Someone on here has done it to their isf, and it looks great.