Tom, Craig
Craig's comments about roots reflecting leaf could have a component of my experience. The deepest roots have been when the green is being established, and the mowing heights the highest. The 'die-back' has occurred when lower green heights have occurred.
We kept our greens somewhat long at 3mm, but have gone longer to 3.5mm (currently 4mm in winter). This is partly to stop them getting too fast (we aim for 10 to 11 feet, closer to 10 feet in summer, closer to 11 feet in winter). When we had a dry weekend a week ago, the greens were faster than 12 feet - no surface moisture thorugh a week long sunny spell, and the time when the growth regulator kicked in the most!
Certainly, the frequent rolling and dusting we have done for the last couple of years has enabled us to keep the grass leaf longer whilst retaining a desirable greens pace.
I've been impressed by the A1 and G series I've seen in Adelaide, Melbourne and Sydney. I'm also happy with our mix of 1019/1020. For my club, we have more significant areas of improvement to concentrate on (trees and light/air to playing surface, bunker re-construction, all-year roughs). We'll continue improving our existing surfaces, and hopefully 2005/06 will be anthracnose -free - it has been on our newer greens (12 years old) but we have faced it on our oldest (25 to 40 years) and smallest (often shadiest) greens over the alst two years.