I did take the full year, I huffed and hawed about it for a while.
The policy was 4 months on full pay, 4-9 months reducing down to SMP, 9-12 months SMP. I really kept a tight hold on my finances so though things were tight, it wasn't uncomfortable.
I had the opportunity to return on reduced hours, but my portfolio content would stay the same and to keep on top of my portfolio would mean doing extra hours [was already doing lots of extra hours before ML] so expectation would be the contract would be for less hours, but in reality doing the same hours, less benefits, holiday and pay. [extra hours were taken as TOIL].
A close friend has returned to work 3 days a week when her DD was 7 months old. She's with a family friend one day, her husband another day and her mum the last day. She finds it hard and stressful leaving her DD with so many people, in hindsight, she wishes she'd just asked one person to do the childcare, as it's the repurcussions of them not following her wishes. She does pay her family friend and mum. She still has a few ishoos, but generally they seem to be settling in quite well.
I've had quite a few friends go back to work at varying stages, quite a few who were determined pre-baby to go back ASAP stayed off the longest.
How much notice do you need to give to return to work, I think it's officially 30 days, but I know colleagues who have made their decision and been back behind a desk in two weeks.
See how you feel at the time, you may find that 4 months on full pay and 2 months on half works for you, give your notice when you feel ready. You can use KIT days to see how it feels.