Well I have recently bought the Zumo 550.
I looked at various models but what I liked about this one was that straight out of the box, I was able to switch it on easily with gloved hand, look though the touch screen menu, look up an address and find the route quickly, can change between shortest and quickest route and yes there are some scenic differencies as I found Saturday on my bike!!
The Points of Interest are useful, especially when low on fuel, in need of a bank or new in an area and need a beverage or food!!
Not sure 4 hour battery life is correct - I am sure its longer as Saturdays run was without a power lead!
I have not yet hooked up to Bluetooth or an Intercom (that is next on my list) but the screen was really clear to read on the move, the speed camera warnings are quite good although I may need to update on the web. Was quick to recalculate if I purposefully took a different direction.
It has a safe mode to stop you setting if it senses you on the move; but this can be overridden.
I have the standard mounting kit on my girlfriends bike and from Motorrad Concepts bought the Zumo power lead with Canbus connector already fitted as well as their Bike Mount for the 12GSA. All installed, very well made and positioned just above the speedo makes for easy viewing on the road. We can now switch the unit between bikes.
I am well pleased with this piece of kit and cannot wait to try it out further afield. We are off to France in June, and I have already looked up the route and places we are staying on it so should have no trouble with the nav on the day.
All the best with whatever you choose.
J