See link for his last summary of units.
https://www.dcrainmaker.com/2019/11/...gy-buyers.html
Note that some may have been updated since then as there is always progress. My personal opinion is that these days most all are decent and it comes down to what you prefer. I really like my Wahoo Bolt due to ease of use and integration with Ridewithgps.com . I have hundreds of routes on my Bolt and the Wahoo app.
Read DC's reviews and think about how you want to use it. Do you want maps? Do you want it to be routable if you get off course? Do you want a major brand? What other sites do you want to integrate with such as Strava and Ridewithgps.
I think once you get away from Garmin or Wahoo you are going to be sacrificing some support potentially etc.
Talk to some friends who can help you get started as even the simple units can stump you some.
I can answer Wahoo questions if you have them by pm.
Alan