I am running 4.1.2 on my GS2 with no problems at all and at least 1.5 days of battery life with moderate use.
You sound like someone who didn't take the time to tweak things on the phone. I can't speak towards how the phone runs stock, but with some slight tweaks and the upgraded OS, its very nice.
I am running AOKP 4.1.2 Build 5.1
He clearly said he misses the "just works" operation. Which I find in many Android phones, "just works" doesn't happen too often. On my GS3 alone, I had to change many things before it felt "okay". In comparison to my previous iPhones, everything worked great out of the box.