My two cents - I got the goggles as I thought they would be useful to pace me in racing. I think they are useless for that purpose, but discovered they are extremely helpful for other ends. In open water, getting an average pace over the entire swim is useless in my view, as noted by others the pace starts too slow (usually it gives me readings of over 3min/100 for the first few minutes), and even if it takes 5 minutes for the pace to settle, those are typically the first 5 minutes when some people tend to go out too fast. HR is not accurate either as it comes from the wrist rather than the chest strap as the strap does not communicate data to the watch while you are swimming. Given that the FORM goggles restrict your vision somewhat (and I have to wear the watch on the wrong side as I am a right-side breather), I won't use them in races.
As for the pool, they are extremely useful as you get real time feedback on pace and stroke rate, among other things. So in my case I was able to discover that if I lift my stroke rate from 60 to 70, my pace becomes considerably faster. I know that in theory you can do that with a tempo trainer, but this is a lot more immediate. Likewise, you can easily implement interval sets (say 10x100m leaving on 1'45) without going crazy trying to remember where the pace clock was when you started the last interval (somehow after the first 5-6 intervals I always forget! and likewise I forget whether this is the 7th or 8th interval lol). they are also helpful if you train in open water as you can finally implement sets like 3min hard 1min easy x 4 without having to stop and look at your wrist to check how much time has gone by. This sounds stupidly simple, but is priceless.
in theory if you use the goggles only mode in OW you can get stroke rate and total time (why stroke rate is not available in GPS mode is beyond me), but again you can also wear a tempo trainer in a race (completely legal) to tell you for example to keep a 70 stroke rate, and enjoy the better field of vision of normal goggles. So bottom line I think they are useless for racing, very useful for everything else. Too bad I upgraded my Garmin as I wanted to use the goggles for racing, and I certainly wasted some money (you do get spotify on the 745 though! ha)
As for the pool, they are extremely useful as you get real time feedback on pace and stroke rate, among other things. So in my case I was able to discover that if I lift my stroke rate from 60 to 70, my pace becomes considerably faster. I know that in theory you can do that with a tempo trainer, but this is a lot more immediate. Likewise, you can easily implement interval sets (say 10x100m leaving on 1'45) without going crazy trying to remember where the pace clock was when you started the last interval (somehow after the first 5-6 intervals I always forget! and likewise I forget whether this is the 7th or 8th interval lol). they are also helpful if you train in open water as you can finally implement sets like 3min hard 1min easy x 4 without having to stop and look at your wrist to check how much time has gone by. This sounds stupidly simple, but is priceless.
in theory if you use the goggles only mode in OW you can get stroke rate and total time (why stroke rate is not available in GPS mode is beyond me), but again you can also wear a tempo trainer in a race (completely legal) to tell you for example to keep a 70 stroke rate, and enjoy the better field of vision of normal goggles. So bottom line I think they are useless for racing, very useful for everything else. Too bad I upgraded my Garmin as I wanted to use the goggles for racing, and I certainly wasted some money (you do get spotify on the 745 though! ha)