At ten inches high when folded, the Evolve SG can be stored under your couch or bed. Both treadmills have speeds from one mile per hour up to six miles per hour. Both have two built in workout programs: manual and weight loss. Both the Evolve and the Evolve SG have a 17" x 45" running surface that has COMFORTzone cushioning. The Evolve SG is a step up from the Evolve in that it has a more powerful motor (1.5CHP as opposed to 1.25CHP), and a speaker system. The speaker system has an in jack that allows you to plug in your MP3 player. That being said, the two treadmills have the same MSRP. The Horizon Evolve SG compact treadmill comes with a ten year frame warranty, five year motor warranty, and one year parts and labor warranty.