I did earlier this year a comparison between the Zumo 550 and the 278. See
here. Maybe language is an issue
but the comparison was aimed towards the
usage of the device. Not what technical features are included or not.
The most important differences I found to be:
- The map details visible on the Zumo screen is very poor making it almost useless for offroad usage or any other active riding on small roads. The Zumo map is 320x200 pixel while the 276C/278 map shows 480x320 pixel. The Zumo is worthless for topographic maps since it need you to zoom in very deep before it displays any minor details.
- The most negative thing I've found with the 278 is its price. The old tech GPS receiver sometime results in receptions problems in deep forests. Another issue is that the screen is extremely sensitive. Touch it once and you have scratches all over!
- The way the Zumo works, user interface & touch screen, makes it the best car GPS I've used so far. It's a very good GPS for beginners and it's great for those bikers that ride their bike as if it where a car.
- The 278 with it's high resolution map and ability to handle tracks makes it, by far, the best MC GPS I've used. It's great for both road maps and topographic maps. It gives an overview of the surroundings, city or countryside, that makes it easy to find alternative roads on the fly.