wish they would work with non apple phones,
or even an apple tablet would be helpful. 
If WOOT would post the MPN we’d know if the blood oxygen app was indeed disabled. Many series 9 new watches are for sale with it not disabled.
I thought about this since buying a series 8 which does have pulse oximetry. When I use my dedicated instrument I get continuous readings. I have another that can record continuously throughout the night if I make the effort, alarms if low, and can review the tracking on my phone the next day.
Why did I even bother to buy into the hype and purchase a series 8? I no longer use the watch.
It still works on my bought-new S9 but is now disabled on my certified refurb S8 (it worked when I first activated it). 
I believe the app was deactivated, in case Apple settles and thus can reactivate. If the device, new or as refurb, left Apple’s hands after a date in January 2024 it is deactivated. If the MPN ends in “LL/A” it was before that date and still active. Hence my comment. Previous WOOT offerings have included the MPN.
I just made this purchase after purchasing the woot Series 7 offer which I’m returning because the battery is dead.
Roughly 80 dollars more than the “New” S7 45mm gps+ cellular, but at least the battery is more likely to sitll be viable and can boot.
s9 Is pretty Good.
It was made After The 2024 cutoff so The Blood Oxygen Is DeActivated.
battery Life 100% still
S9 is the first model that supported the “double tap” gesture, which I love and use daily (e.g. snoozing my wake up alarm). I get confused when I double-tap on my S8, derp. S9 also has a brighter display if you use your Watch outdoors a lot.
Another benefit of S9 … watch covers like the Otterbox ones currently on offer fit S7, S8, and S9. So you can get bumper and cover cases affordably.
I ReTurned mine even though It was Very Good And I was Happy w It.
costco had a sale for The s10 that was $120 Off And I had a $130 gift Card On Top.
The price Between The woot s9 42mm gps + Cellular $299 (Before Tax] And costco 46mm gps No Cellular was $329 (before tax].
atandt Charges $15 a Month To Add The Watch To Your Cellular program so I Realized I didnt Need Cellular. Imagine having Cellular On Your Watch for 2 Years And It costing More than The Cost of Your Watch Itself.
I Went for The s10 46mm And Like The Size And The chip Is a Lot More snappy As Well. battery Life os also Longer And The charge speed Is 15 Minutes Faster According To appl for Fast charging.
The 7, 8, 9, and 10 all feature fast charging. But the S10 has the new slimmer shape so the 46mm may wear more comfortably.