Right

I am being lazy here :-) but I am on my phone and no where near a PC

I have a jailbroken iPhone 4 running on 4.1

I was wondering if it is now safe to upgrade to 4.2.1 and Jailbreak because the last time I checked there was issues with battery drain, so have these been ironed out ? and are they any other issue I should know about.

I don't need unlock

or should I just stay at 4.1

Thanks in advance and sorry I am to bone idol to trail through everything.