New Zealand emerged as the country most likely to be a useful benchmark for Scotland to judge its performance against, given its similar size and geography.
One major difference is the absence of education authorities, leaving schools to govern themselves but requiring the Education Minister to step in when problems arise. Singapore and New South Wales appeared to have less relevance for Scotland given their stronger emphasis on selection.
Singapore, for example, streams at the P4 stage. The Labor government in New South Wales operates a school accountability regime, including basic skills tests for eight and 10 year olds which have proved controversial with the state's powerful teachers' union (despite the fact that a statutory ban exists on the publication of exam league tables).
Mr Peacock said he was surprised by the extension of selection he had come across. "From all that I have seen and learnt, I believe that our approach to comprehensive education, closing the opportunity gap for pupils and keeping youngsters in the education system, is the right one. We are ahead of practice in all three countries.
"Our policy of inclusivity allows us to have a rich range of youngsters in our schools and is no less successful than selective systems."
Scotland's educational reputation remains high, Mr Peacock concluded at the end of his visit. "We are up there with the leaders in our curriculum and assessment changes," he said.
He is keen to capitalise on this reputation, for example by forging links with child protection and school assessment agencies in Australia and New Zealand and by persuading Singapore to buy the Scholar programme for senior secondary pupils and enterprise education materials.
"Wouldn't it be wonderful if Scottish education material on enterprise was going into one of the most dynamic economies in the world," Mr Peacock remarked.