Faster Speed - One of the complaints on lower end models is that they only go up to 3.8 or 4.0 MPH. The Bowflex Treadclimber TC6000 goes up to 4.5 MPH which is a huge improvement and can help you burn more calories with faster workouts. Higher Stability - The Treadclimber 6000 has a more solid feel than the other models. The assembled weight is a whopping 350 lbs (compared to the TC5000 with a 180 lb assembled weight). It feels much more like a health club machine. Plus the deck is longer with more built in support. Advanced Backlit LCD Console - This is the most largest and most advanced console of all the Treadclimber models and is easy to read with 18 electronic functions. Bowflex AdvantageTM - This is only found on the TC6000. The Advantage feature tracks the total workout volume, your last 5 Fitness Tests, and weight loss progress for up to 5 users. This is a great option if you're going to have multiple users. 12 Built-In Workout Programs - The TC6000 comes with 12 built in workout programs including Manual, Plateau, Cross Training, Intervals, The Brooklyn Bridge, The Golden Gate Bridge, and Heart Rate Control. (Workout programs are not offered on other models). Ergo Bar With Remote Controls - This comes with Remote Operating Controls that let you adjust speed while working out. The idea is that you don't have to reach over to the console and this makes your workout easier. Climb Indicator - This is another feature only found on the TC6000. You can see how many floors you've climbed while working out. This is similar to climb indicators you find on stair steppers.