This program is outstanding. The functionality, the fun, the look, everything is top notch. Garmin tried to put out a Mac version of Training Center but it pales in comparison to Ascent. Even the Windows version of Training Center which has more features than the Mac version can't compete with Ascent. MotionBased.com has lots of features, but it is web based and slow even with a fast connection, and hasn't fully implemented Mac support yet. The best Windows program of this type, SportTracks (Windows only), is best described as clunky compared to Ascent. The only significant feature currently missing from Ascent is an ability to download a course directly to your GPS, but I think that has been promised for the future along with other new and unique features.