I'd like a GPS bike computer with a readable screen which actually works for training and navigation. Not integrated because I'll replace it when it wears out (I only got 20,000 miles out of my Edge 500 before the buttons failed which wouldn't be two years at my current monthly mileage) and am not going to get rid of a $1000+ frame because I want to upgrade the computer.

My six year old Garmin Edge 500 (final firmware version) doesn't do maps or give next way point name and distance as main screen data fields. The power connector is on the back where it can fall out when charging while riding which is essential for long rides. The bugs I see are getting stuck on the power meter calibration screen, not not displaying the route after a departure into a store, and being sluggish indicating passing a way point. Otherwise it's fine at what it does.

The brand new Wahoo ELEMNT does maps, has a readable screen, and the UI is good. It wasn't accurately reporting or recording data. It barely does courses - they show up on the maps with chevrons indicating direction of travel, but you don't get way point alerts, distance to next way point, next way point, or a screen listing the next several with distances. The maps lack street and won't pan the map which is a big deal because minor roads good for cycling are invisible when zoomed out. It doesn't do any sort of navigation which is required for turn-by-turn directions following .gpx files lacking cue sheet entries. I sent mine back and bought a Garmin Edge 810. The USB connector is also on the bottom not the back.

The Garmin Edge 800/810 screen isn't very readable in sunlight but they do courses, maps, and navigation. Their USB/power connector is on the bottom.

The 3-year old 810 (they're being closed-out so it's close to as good as the software will get) has spontaneous power-downs, sometimes crashes navigating/following courses, will only display the name of the next GPS guided turn not the way point, tries to navigate backwards on out-and-back courses although the waypoint cue sheet is correctly ordered, sometimes truncates .fit files so they need repair, and has a horrid menu structure - I need to poke the touch screen a dozen times to calibrate my power meter before each ride. I'm going to send it back to replace it with a refurbished Edge 800 released 6 years ago for better reliability.

The 2014 Garmin Edge 1000 might be OK but has poor battery life. Given Garmin's history of releasing buggy software I'd wait a few years before buying one. It's also bigger than it needs to be.

All those have ANT+ support so they communicate with peoples' expensive power meters.

Numerous companies make GPS computers which don't do maps so they're not useful for unorganized long distance rides.

Phones have big screens, but bad battery life - I can't ride a few hours using mine as a bike computer, and it's so power hungry a 3W dynamo hub can't really keep up yielding a string of external power lost messages as I speed up and slow down. Samsungs have ANT+ support in hardware, but the applications don't support it. 4iiii has a ANT+ to Bluetooth LE bridging heart rate monitor, but it sends "composite" messages which the applications need to specifically support

Something is really wrong with technology products when alternatives 1-2 generations older work better.