I've got a Suunto Ambit 3 Vertical, which I bought 12 months ago when Suunto had them on special offer. It's maybe not as accurate as the original ambit (different GPS antenna) but my only real concern with it is battery life. According to the figures I should get 10 hrs recording on 'best' GPS and 1 second intervals. That's enough for 99% of my runs. But what isn't clear is that pairing with other devices reduces this :- so using a chest belt knocks it down to about 8hrs.
What I have found however is that switching the exercise mode to 'trekking' instead of running and not using the chest belt massively extends the life. I'm not overly concerned with HR on extended runs and it's still recording a reasonably accurate track, distance, time, altitude profile etc. So for me this is an easy solution and might be worth considering if anyone else is concerned about the battery life. The ambit 3 Vertical may be comparatively'old' technology but it's still indistinguishable from magic, has a GPS/Baro altimeter, cost well under £100 when I bought it last year and most importantly, let's you configure the face with nice big figures you can actually read.