In reply to BattyMilk:
To add to the Ambit 3 comments - mine has been a serviceable watch for mountain use, with an excellent battery life, for about 4 years now, but:
Suunto has stopped supporting the movescount App and there's loads of complaints about the new app not syncing with the Ambit 3
Downloading even to the old app takes ages / fails if you have a long day out - you have to do it via the cable and a PC
The altimeter now sometimes goes bonkers - yesterday I walked in to do a climb 170m on the way in, 30m ice climb, 5000m total ascent by the time I'd walked out. Mmmmm.
Not a concern of the OP, but I'm on the 3rd HRM strap as the sensor pads delaminate. You have to buy the Suunto one as it's not Ant+ compatible.
I'm now looking at Corus, but I'll keep the Ambit for navigation.