CliftonGK1

If you're not needing the schmancy aspects of the 510 with its colour touchscreen, then the 500 is a great device.
You can set up 3 different bikes on it and then just select from them before you go out and ride. If you have an HRM or Speed/Cadence sensor it can auto sense them, and it will pick up the difference between the speed/cadence sensor for different bikes when you select them from your list.
There's the option to select how many different screens of information the device will scroll through, and you can choose what information will appear on each of those screens. So you can avoid showing things like Power/Wattage, or Heart Rate if you don't use a power meter or HRM, and have it show things like Total Ascent or Maximum Speed or whatever you want. I think there are something like 70 different options to select from.

It's not a colour screen or a touch screen, just a 4 button interface from the corners/sides. It's easy to read, but not overly huge. There can be some glare in the sun, but the mount is easy enough to re-angle it if you need to.