I'm a competitive runner who has switched to using my AW3 full time. I just sold both of my Garmin watches this week in fact.
I use iSmoothRun and a Stryd power meter. Distance is extremely consistent, and pacing feedback is accurate and immediate.
The addition of the ability to use the side buttons for pausing a run or setting a lap is what really made the difference. The only reason I'd need a different watch at this point is for ultras lasting longer than about 7 hours - and I don't have any of those on my schedule for this season right now. I'm hoping that the next generation of AW will get close to 10 hours of run time.
Correct. Stryd operates completely independent of the watch and its GPS. Stryd simply communicates with the watch in order to display its data. If you allow it to, it can replace GPS for distance functionality and it should be more accurate - although in practice I find them to be pretty consistent either way - but I'm not running short distances - typically longer distances on trails - so I don't care much if my watch is off by 100' or so.
Whether the power data is useful as a training tool is still a bit up in the air. Because Stryd has to estimate power rather than measure it directly there is a lot of question about how accurate it is. I've only been using it a short time, but I think so long as you understand its limitations, it provides better info than we've had previously. Pace and HR are not great indicators of training load because they can be affected by so many outside factors. The power reading you get is instantaneous (unlike HR). For me, training on heavily forested trails, getting accurate distance and pace under these conditions was worth the price alone. Seeing how high my power output spikes on climbs helps me reduce my effort in order to run stronger later.
And LOL
@James.K.Polk 'not as competitive as you were'. Sub 2:30 would put you on the podium for most regional marathons and would have put you top 50 or better most years at Boston.