So I just replaced my Zumo665 with the 590 due to H-D advertisement to see the screen in direct sunlight. Although the graphics are awesome, the GPS features are great and YES, I can see the screen in direct sunlight, there is NO SIRIUS RADIO! The 590 will stream music from your phone via Pandora or other services but the Sirius ability is gone. Additionally, the 665 has a nifty zipper case to store your head unit in when you park in public and want to lock it away in your saddlebag. The 590 has no carrying/storage case. These cheap bastards cant even give you a $5 storage case with the unit. So now I start doing the research I should have done before I bought and installed this POS. Garmiin's version has the option of integrating optional wireless tire pressure sensors so you can see your tire pressure right on your GPS screen and if there is a sudden drop in pressure it will alert you. With the H-D version, no such luck. I did get 15% off from the dealership and of course that savings ++ was eaten up by having them install the unit which I later found was installed improperly and I had to return to have them fix it. What ever happened to the days when H-D prided themselves on giving great customer service so you would come back tomorrow? Now they are only worried about how much money they can get from you today and then they immediately forget who you are.