Obviously, other than portability, those devices only offer resistance in a single direction and with very low-level proprioceptive requirement. AXIO Trainers are different in that they strengthen with a complete 360 degrees of resistance while also developing elite-level proprioception. AXIO Trainers are also more progressively challenging and great for all user levels. So as you improve with an AXIO you can progress by varying positions, adding movements, or using the advanced models.