When my maternity leave finished, DH used his Long Service Leave for 4.5 months and was the SAHP when I went back to work Full Time. He was awesome. It worked well for both of us. DS was almost 11 months old when I returned to work and then when DH went back to work and I went p/time (4 days) DS started 2 days of child care at 15-16 months, it worked out well in so many ways.
DH loved not working, he preferred being a 'house husband' for lack of a better time, and was devo when it was time to return to work. At first he found it full on, didn't realise how much of a juggle it was to get the housework, child rearing, shopping, cooking etc etc done, but certainly learnt an appreciation of it real quick and worked out his own routine that worked a treat for him and DS. We are planning on doing the same when DD is born and I return to work as DH has more Leave saved up. I think that the best part was Dad getting to spend special time with his baby/toddler, they both relished in it and I am sure it will be the same again.
When we first swapped, I wrote down our routine, all DS likes/dislikes/moods/routine etc etc as even though DH had an awareness of it, he didn't know DS like I did. He found it useful in the first few weeks, but then never used the info again.

Surprisingly a few people found it weird - eg MIL made a few comments about it early, but then worked out it was too her advantage and dropped around A LOT when I wasn't here. A few mates made a few comments, but in hindsight, I think they realised how much DH enjoyed it. It was a great experience for us and we look forward to doing it again as it makes financial sense for us, as well as all the other perks!