I got the Charge 2 last month and I've been really impressed with it.
It has "connected GPS", which means it uses your phone's GPS - I always take my phone running etc so that was no problem for me.
It's also not waterproof, so wouldn't work for a swimmer.
I really like the auto detection thing - so if it detects that you've walked/run/cycles for 15+ mins it automatically records it as a workout/records the GPS.
I'm finding that it's really encouraging me to do more in terms of non-exercise activity. Thinking about walking instead of driving, or choosing the (cheaper and) further away car park, etc.
It gives a little annoying buzz every hour if you haven't done 250 steps that hour.
It goes nuts on your wrist if you meet your step goal for the day (which is nice!).
The app goes all starry each time you meet a target (steps, active minutes, stairs, etc). And if you do all of them in a day it pretty much explodes!
And it tracks your sleep, pretty accurately. Which is my main priority at the moment. (And it reminds you to go to bed, and wakes you up with a silent(ish) buzzing).
I had one of the first wrist-based HR trackers and this one is so much better.
Oh, and I've got skinny wrists, it's much lower profile than DH's Garmin (vivosmart, I think). I'm really pleased with it.