My simplification was to let MFP do all the food tracking and Fitbit to coordinate all the exercise tracking then give that information back to MFP. MFP serves as my main site. I find MFP to be easiest to enter food/recipes and several of the apps I use, including Fitbit, link very well with it. I think either Fitbit or Digifit are better as estimating calories used but since they sync with MFP that works well for me. I like the "Friends" feature of Fitbit and have generally tried to add "friends" who were at or above my general walking level and use their stats as an extra way to motivate myself.