
The hard buttons on the cradle mount do more than zoom on the map. They are our steering-wheel buttons. Their haptic feedback feels solid, with a resonant click, under gloved fingers. Pressing the + and - buttons will scroll up through screens or advance music tracks. The button with the square toggles through the main screens; hold it for two second and it adjusts brightness. The bottom button says the current navigation command; hold it for two seconds to adjust volume. You can do this and more with the touchscreen, albeit through more steps, no haptic feedback and, inherently, less attention to the road ahead because you have to concentrate more on the screen. The hard buttons are a thoughtful, and perhaps safer, interface improvement.

The cradle mount is much wider than the 660's, but it's not an aesthetic deal-breaker. The cradle mounts for the 660 and Nav IV screw into the BMW navigator mount (part number 71607700742 for the R1200R), which is not included with either of the units. See this realoem.com link for details.

Here is the cradle mount with the pins shielded by the plastic pin cover. Unlike the battery cover, there is no rubber seal around the pin cover. Could be a problem in a downpour.

The connector on the left plugs in to the accessory power port underneath the handle bars. It has three wires versus two on the 660. With this connection the BMW battery tender charges trouble-free, with no error lamps. I don't know if the connector with the blue circles is for newer or older BMWs. I guess BMW decided on a one-size-fits-all, Y-power connector for the Nav IV.
Downsides
With the Nav IV you lose the car windshield mount, the versatile RAM mounts, and the 4-in-1 power, USB, voice wire bundle that included with the 660. I used none of those accessories. I did use the BMW navigator mount, which fits the 660 and Nav IV. Instead of that massive wire bundle I hear navigation commands and music via stereo bluetooth with Etymotic ER6 headphones plugged in to a Jabra BT-3030. With fewer inclusion, the Nav IV still costs $50 more than the 660 ($720 versus $670 with discounts).
Speaking of the pits, Rev. 1 of most Garmin software is buggy as all get out. It seems the public is the beta test, and zumoforums.com is filled with rants about software glitches and diatribes against the folk in Olathe. During both my outings with the Nav IV the screen has locked up, requiring a reboot. And although all of my POI files transferred fine, I'm working with Garmin's IT department to transfer a Mad Maps purchase to the Nav IV. The problem? The Nav IV wasn't listed as Mad Maps-compatible in Garmin's database. Hopefully, they'll iron out the creases in future software updates. Leading edge is the bleeding edge.
