A bit different. I think the AP grading is just based on pace and is intended to be a V02Max approximation. The Suunto one is meant to encompass fitness and running efficiency based on a V02Max approximation from the Firstbeat models, which use HR data and speed data. The info says if you're efficiency is 100% then the performance level would approximate your V02Max. The Firstbeat models have been used for a while by Suunto and Garmin but this score is new. There's a Firstbeat white paper
about it and some other stuff online if you're keen.