I've had a Fitbit One for years. Loved it because battery would last well over a week, it could just sit in my pocket, and gave far better step counts than anything I could wear on a wrist... then one day it went missing...
I've had a Charge 2HR for the past year, and bought a replacement metal band from Amazon. It was a bit bulky, but I adjusted. More like four days battery life, and nice to see heart rate, but I went out of my way to turn off the realtime syncing of step/heart to help save battery on my phone first and foremost. Syncing takes about a minute... that sucks. I like some of the social aspects, and some of the tracking on the website.
Messages come across the band, but not taking advantage of the long screen on the device, instead, scroll sideways, and often difficult to read.
So, last Wednesday, I got an AW3 GPS, and a few things that I really like... the better heart rate data in Health, the charger... the charger isn't a difficult thing anymore... sure, it's a daily/every second day thing, but it only needs 30 minutes. I can talk in to it to turn the lights on or off, or send dictate a message when I'm driving in the car (no carplay). I'm diabetic, and I've had a few dangerous low blood sugar readings over the last year... until I'm able to get some sort of continual blood glucose monitor, this works pretty good warning me something may not be right with elevated heart rate warnings. I wear it overnight, just in case. Then, quickly charge in the morning.
Anyway, this new fitbit seems to have a few strikes against it... The charger, again...noway to respond to texts, and I suspect, at least for now, no heart rate sensor warning system. Maybe none of those are big for anyone that uses the fitbit for general step counts, and alerts when someone is trying to get a hold of them, but I do see some value in the next iteration up.