One thing i will say about the auto adjust machines is..they are not really necessary if you have the sense enough to adjust it yourself...i adjust mine up or down in PSI and actually turned the ramp off so i can get the full effect right away...The ones without the auto adjust are a lot less money if you have to pay for them out of pocket...but i will say this about the auto adjust...if you can afford it GET IT...doesn't really matter what brand it is, they all have one...Fisher Paykel. Respironics, Resmed, B3, Invacare etc....The knock offs are so reliable now that they are hard to differenciate from the brand name...