I've installed the Cortex on our last 2 boats, though I was really on the fence about goung the Cortex route for our current boat. Ultimately, what made up my mind to go with it again was their anchoring app. As far as I'm concerned, it's about the most useful & user-friendly anchor app available.
I use this one the same as I used the last; Wifi for data to our phones for the anchor app and to an ipad for an additional navigation program and nmea2000 on the buss for position,navigation & AIS data on the flybridge and lower helm MFD's. I use the Vesper nmea 0183 output for position data to the (4) vhf radios. It's handy to know I have horn signal capability on the Vesper but currently use the ICOM radios for signals.
My biggest gripe, and I can't believe this hasn't been brought up by other Cortex users, is their damn internal compass. On our Albin, I relocated the thing 3 times trying to find a magnetic-friendly location so that the charts on our plotters weren't skewed and just as importantly, our AIS heading wasn't depicted as showing us "crabbing" through the water on other ships plotters. Garmin finally sen' me a nmea2000 heading sensor to mount remotely ,which I did and it remedied the problem. On our current boat, the underside if the bridge is cavernous compared to the last boat and I was free to mount the Cortex right in the middle of the boat, under the helm with seemingly nothing of any magnetic consequence anywhere near it. I just knew it was going to be a good area but after completing the compass calibration, it *the Cortex) still had an onboard deviation that was skewing my charts. I was really hoping Garmin would have incorporated a feature in the latest software to simply turn off the "hdg" output sentence but they did not. I'm not too concerned about it though, since I have a precision 9 compass that needs to be installed on the nmea buss and the Vesper will revert to it once online.