This is one of the most basic things to consider about buying a GPS for motorcycle use IMO.
A lot of people just use a GPS casually, exactly as you mention. This is all fine and well, is no doubt the biggest group of users, and it really kicks the door open IMO to using the 'wrong' type (car) of GPS, or a cell phone, and everything else.
On the other hand, I bank on my GPS and need it to work and work efficiently and correctly. I need to see it in sunlight. I am counting on it to get me somewhere, often someplace I am not familiar with, in a fixed amount of time. On top of that, I use it to find things along the way, the most important being fuel. That is why I carry multiple GPS's with me on trips as Chet mentioned and why I get pretty cranky when they fail.... and I have had so very many fail (over 20 now). I have had them fail in far away places while depending on them to get me somewhere. I have had them fail in foreign countries while depending on them getting me to / from work and my hotel! Not good.
And that is where the value comes in. I would be the first one to suggest that the casual user use a cheap automotive GPS with a baggie thrown over it in the rain, or put in a weatherproof box (cheaply available). But if a person is going to really count on a GPS on a bike to get somewhere, I usually suggest a daylight readable screen, weatherproof GPS and the motorcycle units are really one of the few options in that arena.
I was telling the story of how I went through GPS after GPS at one of my first COG social events, a meet and greet in New Jersey. Now we were all sitting there laughing about it and I am sure some people thought I was telling tales..... When we walked outside, I could not get my few week old (!!!) Zumo 550 to power up! I handed it to one of the guys who had been thinking I was exaggerating (it happened to be Cap'n Bob actually) and asked him to power it up. He could not. Now I was in New Jersey, three states away from home, and had no idea where I was (road speaking) or how to get home. I whipped out ANOTHER GPS, powered it up and tie- wrapped it to the Zumo mount and made it back alive. I always travel with two functional, working GPSs but if going a long way, I carry three.
Brian
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Since I don't travel with purpose a lot, I usually just don't care. I just drive around and explore, confident I won't ever get lost because I can just press "home" or whatnot and get routed back easily (or enter a destination and get there too).
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