I use a Garmin eTrex 20x mounted on my stem. I've been happy with it, zero complaints really.
The only thing is it can be difficult to see in bright sun unless the screen is facing the sun. I sometimes have to turn the backlight on high in mornings when the sun is low and not positioned well to illuminate the screen. It's a minor irritant. I get about 25 or so hours of reliable use from a pair of batteries, IOW about 3 or 4 days using it all day on a tour.
I'd spring for a 30x if I was doing it over. There's a minimal cost difference and the navigation itself is the same but you gain a barometric altitude sensor and the option to add cycling accessories like a cadence and heart rate sensor.
You can see how it mounts on my bike here. It's solid, easy to use and see, doesn't bounce around at all, out of the way. With 3/4" riser bars and Cane Creek bar ends I can almost flip my bike over without it touching the dirt.