“I have a watch SE first generation would I notice a big jump to the series 9?”
Yes, you will!
First and foremost, you're getting ECG, blood oxygen, crash detection, and temperature sensing. Major gains.
Second, you're getting a noticeably larger display area. That's a great advantage.
Third, you get fast charging with the 9. I have it on my 7 and, for example, the other day it had inadvertently gotten down to 2%. I put it on the charger, took a shower, got dressed, picked up the bedroom a bit, and when I returned to the watch, the battery level was already 93%.
Fourth, depending on how much your SE battery has been used, you’ll be getting a brand new battery, so the Watch will last longer.
Fifth, if you keep your old watch, you can swap between them, and always have a watch ready for sleep tracking.
Finally, keep in mind that the Watch 9
requires an iPhone that can run iOS 17!
”Apple Watch Ultra 2, Apple Watch Series 9, and Apple Watch SE require iPhone Xs or later with iOS 17 or later.”
Our most capable chip in a smartwatch ever. A magical way to interact with your Apple Watch. And a display that’s twice as bright.
www.apple.com
That disclaimer is buried in the fine print way at the bottom of the page, after footnote # 28!