I've gone for the Ultra. But I'm keeping my S5 for those odd occasions where I might want a slimmer watch. Didn't really see the point of saving £80 by trading it in when I can still get some use from it.
I’m probably doing the same. The value of my Series 5 isn’t much now as it’s three generations old. I figured I’d just keep it for those occasions when I need something smarter. I’ll wear the Ultra as an everyday watch.