It's an interesting technology, but my main interest in the tech doesn't parallel how they are marketing the product.
I think Sm02 is more valuable information than the lactate measurement. If you can monitor Sm02 you can pretty accurately pinpoint the aerobic/anaerobic switch, zone, or level. You'd also be able to gauge the effectiveness of your anaerobic intervals to verify your target wattage is sufficiently de-oxygenating the tissue, and that you're adequately recovered from that interval to hit it again. The really interesting part is that they seem to be collecting that info, but then use it to calculate lactate.
There are folks that claim the only metric that matters is power, and they're right. If you can't muster the watts to bridge up, or remain with the group on a climb, then that's that, you've failed. The ability to do the work matters most.
What they fail to take into account is that lactate measurements tell a fair bit about how your body is making power across a wide power curve, and the ability to monitor that curve over time tells an interesting story, and for me personally, has completely changed the way I use my power meter to begin with.
Taking a multidimensional approach to analyzing your power curve is worth while, and having the ability to monitor Sm02 would really be quite interesting.
I have my own reservations about the traditional definition of FTP. The number is a moving target, and the work you're able to do relative to FTP is influenced by a number of variables, diet, hydration, fatigue, recovery, etc. The thing that I've noticed is that on bad days with fatigue when you struggle to make power, or after getting dropped on a climb, that wattage I settle in at, is, you guessed it, lactate threshold. If anything it has been more consistent for me than traditional methods of FTP testing. My best 95% of 20 min tests are a solid 35w more than lactate threshold, and 40k TT power has been maybe 20w or so higher, FOR ME. I generally do my lactate test and power testing very near each other after training blocks, and use 1/2 way between the two as my FTP, and even then I know my Sweet spot is below suggested % we traditionally use to find it.
What regular lactate testing has taught me is that, a) I used to train far too hard when I was trying to train the aerobic engine, b) I wasn't consistently training hard enough anaerobically , and c) that my increase in FTP was largely from anaerobic intensity work.
Which meant I was passing up the bump in FTP from doing adequate aerobic work, the gains I had been making were quick(er) to leave with decreased training volume and intensity, and the work I was doing that was increasing my FTP was too easy, and too infrequent.
To end a long rant, I'm two months closer to my high water mark of last season, and I've ridden far less this early season than past years.