[Q] Buying AT&T Note: custom ROM REQ for batt life & stability?

[anon(220176)]

Just to give context of what I am trying to get, here's the background information:

I had HTC Thunderbolt and the stock Verizon ROM was really bad.
ISSUE: bad battery life, crashes, random reboots, etc.
SOLUTION: I tried MANY custom ROM and after a long time, found one that works great and stuck with it for months

Afterwards, I bought an International version of Galaxy Note, a CARRIER-UNLOCK phone with none of the carrier crap or firmware. The stock ROM works great, so much so I don't have to install a custom ROM
- ISSUE: NONE! Great battery life, really fast and buttery smooth
- SOLUTION: NONE!

Unfortunately, my International Note went defective and it was not covered under Samsung Warranty. Not wanting to go through the same non-warranty issue, I am planning to buy the AT&T version of the Note.

So my question is:
Using the STOCK AT&T ROM, do YOU get the following:
- Good battery life (at least 8 hours - I don't mind rooting and freezing some crap)
- Fast OS performance (not laggy, etc.)
- Stable OS

I don't care about ICS or what not, I just want something that works with the above.

I am just trying to figure out if I have to go through the same thing when I had my Thunderbolt (see above) or not.