I have a Garmin 500 and it has served me well, but it is going on 7 years now and who knows when it might expire. I monitor a few Strava segments as one of several indicators of conditioning and how I am improving or not. Others may do it differently, but as I said, this is one indicator for me.

If I get a new GPS unit, is there one (Wahoo, Lezyene, Garmin, Polar) that has a better implementation of Strava Live Segments than the other? It seems being able to have some almost real time data about how I am doing on a segment compared to my PR would be useful for my purposes.

What is your experience using this feature?

I have a Garmin 520 and love it for the Strava Live Segments. I can see how I am doing compared to own PR in real time. You have to star the segments on Strava first then sync the Garmin to get the live tracking, but that is pretty manageable.

Wahoo claims for its Elemnt that one reason they've gone with a fairly closed system that's compatible with only Strava (and maybe one other) rather than open source, is because they get better accuracy and consistency. No idea whether that's just marketing hype. There are a couple of good in-depth reviews for the new Elemnt online. Out of my budget, otherwise I'd consider one.