The list of differences is much too big to post here... it's almost not fair to compare them. For starters, GSAK is designed to work with all the custom GC.com cache data, such as logs, hint, cache status, difficulties, container type, hider, hide date, TB's, etc, etc. GSAK's filtering capabilities are staggering: any field can be filtered on in combination with and or all other fields. It's very easy to set up a custom filter and save it for later recall. Let's say you want an easy caching weekend someplace to the north: set up a filter for all caches N, NE & NW that have difficulties less than 2, less than or equal to 1 DNF, and less than 30 miles from your home coordinates. Or if you are travelling from one cache to another, and would like all the caches that are less then 5 miles from the line that connects them, it's another simple filter. I can also filter by text, so if I'm heading to Portland I can search for all caches with the word "Baxter" in the description that I haven't found yet.Originally Posted by ribnag
It will also maintain a list of your FTF's, the date you found a cache, and it lets you add notes and correct the coordinates (handy for puzzle caches). You can change the center point of your distance measurements which is handy if you're out camping, visiting or travelling. If has built-in links to all the popular mapping websites, and it's very easy to add your own link (I made one to USAPhotoMaps). For power users, the macro language is a bonus... you can make it do just about anything, from statistics on all the caches in the state to creating a custom web page listing all your finds.
It can also upload to most GPSr's as well as send the data to Cachemate (or other PDA s/w, I assume), so if you have all your caches filtered, it's two clicks to get them all to your GPSr and PDA.