I have had a day or 2 with the new 590. here are some of my thoughts
processor is much faster. does not take anytime at all to have it plan your trip
the screen being larger is nice for older eyes like mine
smartphone link
cool for live data from phone, traffic, weather
audio seems much louder and better
service history is nice. not sure I will use it as I keep that info in another place but it might be nice to have it in the gps
TPMS is very nice. I have had it for a long time on my gold wings and so I am not ready to be without this info
lane assist is nice to know ahead of time which lane I should be in
posted speed limit for this road is nice. I never seem to know this info. it is not 100% but it is a feature I like
one thing that was strange this morning on the way to work, with lots of traffic, the bluetooth feature told me it had found a new device (it was from a car close by) and wanted to know if I wanted to pair and play music from it