Just "downgraded" from Ultra to Series 10. I don't need Ultra anymore, because Series 10 does measuring water temperature. Happy that it's half of weight, thinner and minimalistic just like the fitness/health tracker should look. I'll just have to speculate a bit with the battery during the day.
If you are not sure about the bigger size and you have a small wrist, I think the choice of strap is very important.
I think sport band looks much more better then sport loop on my wrist. There's my
previous post of Ultra and post comparing
Ultra vs S4.
Here's 46mm size on my 16cm wrist.