Here it is folks, Onecosmics RC2.11 (Ice Cream Sandwich) ROM review from my first day of usage:

Battery

after 12 hours of usage i still have 17% left. in total i made 16 calls, nonstop messaging on Whats App, a few smses about 10 minutes in total of web surfing and facebooking, snapping 7 pictures, as well as using bluetooth to transfer a couple files from PC to phone. brightness is set at 65% and network was on 3G the whole time.

Response

The firmware is pretty stable. i could play all the videos on my phone, including ones that i recorded from the phones camera, and ones that i downloaded from the internet (mostly movie trailers in HD). switching from menu to homescreen, opening up the web and going through apps and folder was quick and snappy. rebooting the phone is much much faster that when i was on Darky. do note that i only restored about 5 apps, and have at least 40 more remaining.

Glitches, Problems, Missing Features

there appears to be no zoom option when snapping photos, so im guessing it will be fixed in the next ROM release. Camera is also not as good as it was when running on Froyo or Gingerbread. Face unlock is kinda rubbish, so dont expect to wow your friends with that feature. there is no USB mass storage option on this firmware so that might dissapoint some of you out there, however there is a fix (not so stable as it may not work for some phones) for that problem HERE.

Conclusion

So far im liking the ICS ROM from Onecosmic and although it still has a few glitches here and there, im still kinda happy with it. makes my galaxy S look like a new phone  . battery life was ok seeing as my usage today was moderate. 

tomorrow i will be testing the battery life with 2G network for the whole day.

Hope this helps! feel free to ask me anything aaite!