I use the Ambit & have done since it was first released.
I only run off road & long distance, so its well suited for the info I need, such as altitude, ascent, decent, plus the navigation features are good for guidance. However, at present, there are no interval timers (due in Nov update though).
If you run on road or well defined trail, its probably overkill, but if you are more adventurous / ultra type runner, its worth considering.
Personally, Its a great tool for me & I wouldnt swap it. Suunto seem committed to the firmware updates too, adding new features & functionality. The other thing to consider is the S/W to analyse the data ... Movescount v Connect