Before I bought the 276C I did some work comparing the different models to se what fitted me best. What fits me best doesn’t necessarily fit best for you…

I got curios about which automotive functions the 276C doesn’t have. It has custom route preferences (Route/preference/Calculation method/Avoid U-turns, highway, tollroads, unpaved roads) and what you call look-ahead" POI lookups” (Near current route, near next, near second or near destination).
What exactly is the difference here between a 26xx and a 276C?
I use mostly topographic maps anyway and they don’t support route options…

When it comes to memory capacity the 26xx is far better, and memory is nice! The problem is that for the places I would like to go there is no memory-consuming maps so I have no need for the memory… Sure there will come good maps for Africa, Russia and Asia but we are not there – yet.
Even here in Norway the topographic (1:50.000) maps (which doesn’t require a lot of memory) is far better then Garmin maps, they don’t have the route options but unlike Garmin maps they have the nice roads, and IMHO that is the main purpose of a map!
This will change in a couple of years and for people who travel in areas with good maps and prefer that the GPS should find their route memory is a concern, for me 256mb is a lot…

The screen on the 276C is far better (and bigger) then the screen on 26xx. The 276C has a TFT screen with high resolution compared the LCD screen on 26xx. IMHO it’s hard to see the screen on the 26xx if it is in sunlight or it’s covered with dust. The fact that it is a LCD screen makes it hard to see from different angles, like when standing up. If you have to use time (and focus) to view the screen you have a problem…
The buttons are maybe a matter of taste but don’t buy anything before you have tested it – with gloves.

Personally I think a battery is nice to have (my old unit didn’t have one). The 276C has a rechargeable battery which makes it possible to remove the unit from the bike and plan next day driving in your tent or somewhere else. The 26xx doesn’t have a battery.

Other subjects are: (26xx in brackets)
Number of waypoints: 3.000 (500)
Trackbackmode: Yes (No)
Tracklog points: 10.000 (2.000)
Nightmode Yes (No)
Tide Prediction: Yes (No) (never more get stuck at beaches?)
More info can be found at www.garmin.com

When it comes to the price for long distance touring I will say that you are better of if you choose a 276C for a Trans Africa trip then a more expensive 26xx. Maybe it boils down to the definition of long distance touring?