I have a 38mm Series 3 LTE+GPS, and I can get three days worth.
As to your point about running the batteries down. If you do upgrade every year, or have AppleCare+, then who cares about running your battery down. If it fails, Apple will replace it. I usually always upgrade my AW every year, however, the Series 4 (in my opinion) just did not offer enough to upgrade. First time I did not get the new AW. I will most likely buy the Series 5. Just curious what Apple will add to the Series 5 to make it worth the upgrade over the Series 4. If it is nothing super amazing, I will just get a Series 4 brand new, for much cheaper.
Also, the battery is holding up just fine on my S3 obviously, if I can get three days of use on one charge. Also, I have AppleCare+ on my AW, so if my battery starts to suck, Apple will take care of it. I have never made a claim on the standard one year warranty, or AC+.