Got it about a month ago on my German Note.
+1.
I have had my JellyBean update about 3-4 weeks.
I must admit, I am not overly impressed, I have noticed a considerable reduction in battery life, since upgrading Firmware.
4.0.2 = 24-48 Hours.
4.1.2 = 18-30 Hours.
Today for examaple: 100% Charge
18.03 Hours From Charger.
15~ Hours Standby.
3~ Hours Screen on (Some light internet usage + Reading a book)
An I am at 5% Charge.
I Disable all unused functions, an clear memory while in standby.
An even still the Phone wakes up (Screen Kept Off) while in standby mode, an does some unusual processing.
In actual fact; I might try a factory reset later to see it that helps maters.
PS: Still love the physical hardware + screen. An will by hard push'ed to upgrade to the Note3, when it's announced.
Especially considering the Exynos 5 (Galazy S4) is only 4 Cores + 2GB Ram: Its not a revolution in hardware upgrades...