Just came back after a two-hour test session with the mount (with an 80mm refractor, I even tried the heavier 2" mirror). Overall quite happy, it's finally a Go-To, WiFi, no-additional-power-supply-needed mount that I can take in carry-on baggage or whenever I go camping. The optional column was useful, I was able to point the scope straight up, something I haven't been able to do in a while with other scopes because of clearance.
After more than hour after the alignment it was a bit off in go-to (the object was just a bit outside of the view through a 40mm eyepiece), but cannot say that it was the mount since I fiddled quite a bit changing eyepieces and mirrors.
The one problem, however, was SynScan Pro crashing whenever I tapped "Back" from the screen showing the object details. I restarted the app, re-connected and was able to resume work as if nothing happened (had to do this everytime). I already emailed Skywatcher support, I hope they'll fix it soon.
I also tested
- whether the alignment holds if I power cycle the mount itself. It didn't, any Go-To command moved it in completely different parts of the sky.
- whether I can use two devices at the same time (tablet and phone). I aligned the mount with the tablet and then also connected with the phone. I was able to move the mount with the phone (it was useful for fine adjustments at the eyepiece, since the phone is easier to keep in hands than the tablet) but I couldn't use the phone to issue goto commands. The mount didn't move then it didn't answer further commands. This is not a scenario that's advertised to work, I was at the end of the session and just tried it to see what happens.