Thanks for that. I'm hoping it is just a cycling issue, it's already behaving a little better today in standby although actually using the phone is still hitting the battery more than ICS did. Also, like a fool, I forgot to re-enable Juice Defender for the first 24 hours 
I thought that might be the case with the full data wipe version too, so that's the one I used. I'm just undecided on whether I should have tried the rooted one instead, although that would really be for apps rather than a great desire to tinker with the phone's workings.

I thought that might be the case with the full data wipe version too, so that's the one I used. I'm just undecided on whether I should have tried the rooted one instead, although that would really be for apps rather than a great desire to tinker with the phone's workings.