Quick answer, I expect the Garmin 478 will be mounted over 50% of the motorcycles in next week's Iron Butt Rally. They are superb rallying GPS's and when one comes up on EBAY or Craig's list they are snapped up instantly. We have a few 478's as the Garmin replacement 496 is approximately $1,400.00 used.
It is too bad that the newer GPS's are dumbed down and not as good for detailed route making and competitive Rallies.
I have had a few GPS units over the years, all Garmin products, and I have dealt with the various foibles, screen de-laminations and units too old for upgrades.
I started with the original Street Pilot 3 (Colour), then moved up to the 2610 nd 2820.
At one point we had 3 2610's and I just gave away the last one. I also had a 2820 which allowed very limited weather , XM radio and my only voyage into Bluetooth technolgy on a motorcycle.
We begin to switch to the upgrade above to the 276 with the 376 C and have since sold the.
Currently we have Garmin 478's on our bikes, which gives us excellent daylight screens, XM radio and top notch weather real-time display. The lifetime Garmin map updates are apparently having some issues on the latest map upgrade ( too large a file)
We are traveling to Europe for some two up riding and have set one of the 478's up with the European map sets.