I've had every Note phone and the Galaxy S phones 1-4. My mother still uses my Vibrant that I purchased in September 2010. My original Note has battery drain issues. Other than those two, I actually still use all of the other phones as side devices on a daily basis. My rooted and ROMed Galaxy S III has some glitchiness and my Captivate Glide burns through the (small) battery pretty fast. However, they are still very usable devices.
I honestly think that the Note II was the best phone that Samsung ever built, both for the internal and external hardware. I'm not saying that the other phones are poorly built, but I agree with the other posters here that have said that the Note II was a great device and we really didn't "need" to upgrade from it.