@dbg: Evidently you're doing different sorts of tours than I can imagine. I would never dare look down at GPS while riding. I'm even reluctant to glance at my bike computer to check the speed going downhill. Simply too dangerous for me. Also, there may be a single dozen turns per day for me, not multiple dozens. Some of those turns I can keep in my head, others are a good excuse to take a rest break and look at my paper maps. So even if a GPS was my only map, there would be no reason for me to keep it running all the time.

And true, I didn't take the Garmin devices outside into direct sun. But REI stores are quite well-lit and have sunlight coming in the windows. Regardless, even if the Garmin transflective displays really are that great in sunlight, my Nokia N8 and the iPhone are also perfectly usable in bright sun. The whole world is using smartphone outdoors.

Anyway, I asked the REI guy to show me the top-of-line GPS they had for sale that used batteries (rechargeable isn't an option for me on tours). It was Garmin, but don't know the model. Compared to a modern smartphone, I was appalled at how clumsy this device was to use. No pinch-and-zoom or panning via swiping. Rather, you had to push a + or - button to zoom and arrows to pan, or something like that. Resolution much worse than on my Nokia N8 or an iPhone, meaning not really that usable to get an overview of the area and trace my way along the road to get an idea of what lay ahead. Maps all had to be purchased separately, adding to the already high cost. For my type of cycling, the device was clearly a step down compared to the Nokia N8. For hiking purposes, such as the Pacific Crest Trail, it was also a big step down compared to a combination of high-quality paper topo maps and a Garmin Foretrex 301, since the maps on the mapping Garmin GPS I examined were so much inferior to my paper maps (which I won't go without when hiking the PCT) and weight was so much heavier than the Foretrex 301 non-mapping GPS.