Haven't read much about them, but still probably not worth the trouble. You either have nitrates or you don't. I was fine with my api kits that were basically 0-5, 5-20, 20-100. I bought the salifert kit to double check, but it's also am easy kit to get a good reading on low range nitrates too, so still not worth the hassle of the colorimeter.
To each their own though. I definitely appreciate the value for people who have colorblind or other vision issues, but for most people amd most tests, it seems not worth it.
Believe me, if it were easy, I'd drop chemical testing kits on a second. I was so excited to come back to the hobby after a 3 year break and see all of the colorimeters available. I would have bought them all instead of test kits, but after reading reviews I realized that they just aren't quite ready yet for prime time. Almost there, huge gains made, and it's fantastic that they're available to us now, but they're just a hassle.
The question is whether these new multi test kits and controller interfaces can really replace testing in general. I'm referring to the senseye amd whatever that Kickstarter one was.