[Galaxy S II Q&A, Help & Troubleshooting] cwestpha:
Placing this here even though it isnt a Q&A but it does have some advice and can give people some information if they have questions about CM7.1 nightly & their Galaxy S II.

Played around with this a bit and am now just writing up my experiences with CM 7.1 nightly for Galaxy S II on AT&T. Rooted my phone using CF-Root 4.1 -> XXKG6 frankenstien -> CWM delete user+swap -> CWM mount SD (note external micro sdhc is shown as emmc as external SD is actually internal extra memory) -> CyanogenMod nightly build 16 -> CyanogenMod nightly build 20 (was released a few days latter).

So far I am loving how quick and responsive it is, as you expect from Cyanogen. Hardly any crashes and unlike my galaxy tab 10.1 the XDA app doesn't always crash. I am quite surprised how far they are along with supporting the hardware for such a low build number.

Some things I have found (build 20):

* Bluetooth only kinda works

- Detection, pairing, etc work

- Re-connect (automatic and manual) doesn't work. You can get around this by re-connecting as if setting up for the first time.

- Headset profile doesn't work (push button does but audio is horribly garbled)

- A2DP doesn't work

- phone book/contact sharing/sync doesn't work

* Noise Canceling using Samsung's built-in capabilities (closed source by Samsung preventing adaptation)

* Doesnt like my Jawbone Companion (mostly side-effects with the poor audio quality and other bugs involved in the still developing bluetooth stack)

* OC isn't supported in the included Kernel (1.2 Ghz max) but to most this is more a feature then anything. ^.~

* With the google apps gtalk video chat doesn't seem to be supported. Not sure if this is a ROM issue or an issue with the google apps included.

* tons of developer stuff not needed in the final ROM, sure its mostly just included for aided development of the nightlies.

* Camera options are still a little sparse but everything there seems to work and resulting photos exceeded my expectations.

* WPS doesn't work via push button OR either PIN method.

A few notes/tips for new arrivals:

* keep firmware backups & app/settings backups on a microsd card along with at least one recent CM build and one based on stock just incase.

* things stored on said card wont be shown by default in recovery unless you mount emmc. Consider this an annoyance and a blessing. Less likely to screw up just doing a normal backup or restore.

* The modified clockwork mod included in CF-Root 4.1 is fine, but cant simply be replaced with the ROM Manager's version until you move off of the CF-Root rom build. Just use their CWM thats included in the wonderful CF-Root and use that to do your first flashing. Using the "official" ROM Manager with the modified ROM manager causes drama and issues.

* Make sure your phone is set-up and everything works before going to a nightly like CM. Flash to the latest Radio your phone, carrier, and sim like and dont panic if you have to move back one or two released builds. Its just easiest to update all of that stuff and get it working before going to something potentially unstable with its own potential issues.

*If you still feel a little concerned then nightlies aren't for you. Odds are you wont break your phone, but you can end up with not having your phone in a usable/ready state for hours or days as you try to piece together how to fix it.