Definately go with the Savage X, if you are buying new. The SS and the Savage 25 are the older versions. The newer Savage X comes with some needed upgrades already done, such as the 4 spider diff mod and the Cam style steering. Also, there were some new modifications made, to make it a little easier to work on. The oldr savages were a P.I.T.A. to work on the diffs, the Savage X has made this a LOT easier.