Again, I think your comparison point does not make sense. I started with S9 Vauto and when my insurance offered a new machine, I tried the equivalent Dreamstation. While I liked the design of the DS, I strongly preferred the ResMed. I don't know how to describe it other than saying the resmed breathing pattern/feel seemed more natural to me. So, I swapped the DS for the Aircurve 10 Vauto.WARREN_S7__VPAP_III wrote: ↑Wed Aug 07, 2019 4:58 am
Ward Medical Services —- President Earl E. Ward, of St Augustine, Florida 32086, is Offer Me, the AirCurve 10 - s @ $1,750.00, $437.50, 4 Month Installments and the VAuto s9 @ $750.00, Not Sure With the 4 Month Installment Plan, If so, $137.50 For 4 Months. He has NEVER - OUT - OF - THE - BOX Models Of the s9’s, since ResMed Discontinued the s9, according to the ResMed Publication On Online, Date: 2016 JAN 11!
To be very clear, I would personally not purchase the AirCurve 10 -S. I find great value in an auto adjusting machine which the 10-S lacks. So, given what I think your criteria are, it is time to compare the two Vautos (10-Vauto and S9 Vauto.).
I personally like my series 10 machine over my series 9 machine. Hose routing is slightly better. Nicer color LCD screen. IIRC, auto humidity was a new thing. Seems about as quiet as the S9. Breathing seems a bit better as well (could well be a mental thing). At some point, manufacturers stop supporting older units and supplies/parts can be more difficult so I prefer newer in that sense as well. That said, this is in no way a current problem.
On the down side, I like the fact that the humidifier unit can detach in the S9. Humidifier tank design is a bit of a toss up -- there are goods and bads to both models.
For the sake of argument, I am going to assume you are buying cash with no insurance. If the price choices are $750 vs $1,750, I am going with the S9 Vauto. Otoh, if I can get a used Aircurve 10 Vauto for $550, I am doing that over a new-in-box S9 Vauto at $750. And, again, I am not getting the Aircurve 10-S.
Birthday 
!!