7X Pro Sapphire Solar, not so long ago I made a choice to stay with 17.28 due to all the problem all after 17.28 have. I am not saying it is the perfect, but at least the watch does not crash, battery seems to be OK, pairing via Bluetooth works with HRM sensors and keeps constant connection (tested with Suunto Smart HRM), as well as DEM calibration does not require constant phone connection. ECG is also available with 17.28, so I don't think I am losing something compared with the latest firmware releases which if I have to be honest does not offer something new, rather than more headache with crashes, bugs and connection drops.
I stayed on 17.28 and do not think I am missing out on anything. I wish I stayed on 16.22 though, in 17.28 an unwanted feature (audio instructions during navigation) was introduced. 17.28 did not give me any reboots, I trust it.....
