Trygve

I have a 2006 SC430, I have ver 5.1 Nav system installed, Dealer tells me Ver 10.1 is available, just bought the car a few months ago. Nav upgrade cost is $299. plus tax which is 15% here in Nova Scotia, Canada. Can anyone tell me how different or better the new version is than my current version 5.1? Is it worth upgrading? I am really enjoying this car. Just wish we had more sunny days here in eastern Canada. Cheers, and Merry Christmas to you all. Regards, Tryg