There was this nagging problem with CM9 roms (irrespective of stock or Siyah kernel) where in I was not able to play videos of a particular 720p format, (unfortunately all movies that I watched on my phone were in that format) http://db.tt/ErqlGi3S
in the hardware decoder mode. I was successfully able to play the same in mx player in s/w fast mode but in h/w mode got a "this video format is not supported error message"(logcat attached). However the very same video file played like a dream on Sammy ICS roms (irrespective of stock or Siyah kernel) in hardware decoder mode in mx and dice player. If that wasn't enough, I was able to play sample 720p, blue ray format video files uploaded by various xda members on cm9 roms in hardware decoder mode except for the ones that I have just shared.
Today Codeworkx confirmed that it's the google aac encoder which fails on my video, he wasn't even able to play the same video on his Google Nexus. It seems Samsung provides its own aac encoder.
I am extremely happy that now with the double boot feature, I am able to switch to a Samsung ICS rom to watch/present movies/presentations made in the shared format in the h/w mode. Thank you for that
BLN works like a charm for calls and text on both roms(phone sleeps well and no wakelocks