i really dont like the price points of any of these bike computers , they barely have enough storage and few allow micro sd cards to hold all the maps , i use the garmin 520 and its a cool luxury but its not very valuable for the full price of over 200 bucks or even the used price of 150 , my phones combined dont even cost 250 and they both work flawlessly , with only the slightly annoying aspect of mounting them , they can brake over time from all the bumps and bangs and with internal batteries can go dead on a ride , but i have gotten by for years with a 50 dollar Samsung and it ran my navigation, strava and music perfectly .
out side or races or trail rides , or displaying your sensors the dedicated head units just dont justify the money they cost when a phone can do everything they do for way less cost , but the head units are very fine luxury to have .
one option i used for a long time and still do even after my head unit acquisition , is OSMAND , this is a gps navigation app thats free and can store very detailed maps of entire states , display multiple tracks and can even edit and create tracks on the go , as well as being free and WAY better than any gps head unit , and i would just carry a battery pack or two with a long usb cord that would charge my phone or head unit on and off for the entire ride .
If you do have the money and dont care about spending i think there are many good choices , wahoo and garmin have the lead with lyzne close behind as well as many other makers coming out , i would just make sure the unit can accept micro sd cards and can redirect routes on the fly , a touch screen to zoom in and out helps too .
one more thing to keep in mind is a lot of these units dont last any much longer than a phone , and the ones that do cost around 300 plus dollars new to equal the battery life of a phone , and i would end up having to plug in my head unit anyway to finish the ride , and if i wanted to use the blue tooth feature it would be impossible without the external batter pack , which i was used to anyway , but it kind of eliminated the advatage of a small independent head unit .
ONE more thing to note is i also used to use OSMAND with its turn by turn voice navigation in my ear with wireless earbuds , so sometimes i would not even have to look at any screen and i could just ride and be buttery smooth in my NAV without worrying about looking down , even when i used to use google maps on a phone with no service , it would still give me voice TbT nav and i would just find a mcdonalds or dunkin and load my return route back home on their wifi !!
Oh and extra note , strava used to accept sensors on the app but no longer does for a while now , and thats the only reason why i even bother with a computer , i used to use a tiny lzyne micro color just to get hear rate , and the strava phone app just bugs out when ever another cycling computer gets too close , they still havent fixed the app , but it seems to work better with more modern phones that have the more advanced gps chips like the even galaxy s7 !