Which custom or official kernel should I use on SGS2?

Question

I'm using SGS2 with latest stock ICS ROM, but it has few bugs which I really hate, so I want to look at custom kernels which could help me in this.

The main headache for me at the moment is I can't turn off my SGS2, when I try to do this my phone reboots itself so I need to pull out the battery to Switch it off. I'm getting hardly 24 hour battery backup while I'm not using too many calls or internet on my device, if I charged it 100% at night and wake up in morning then it drains out 5-10% battery. I have disabled auto sync, network connection etc which could be cause to drain out battery fast. Why I'm looking for custom kernels are due to

1: I want to get good battery life.
2: I want a good and stable performance.
3: Don't want to lag while playing games like Temple Run

I have heard two custom kernels for SGS2 are Siyah and Speedmod. Now I'm not sure which one should I use to for my phone for getting a good performance and battery life.

Can I flash kernel using stock recovery of my SGS2? And is it safe?

Answer 1

Upgrade your phone to latest JellyBean stock ROM and flash SpeedMod kernel from Odin. Right now is one of the most stable combinations for the Galaxy S II.

If you want more performance you can always install Siyah kernel and tweak it for your needs.

Also remember to do a full Nandroid backup before flashing anything and wipe /system, /data and /cache before installing JB from Odin.