The Kookaburra is not "just a ball" really, the seam is nowhere near as pronounced and it goes soft very quickly. So after 20 overs there's very little there to work with, it impacts on Australia home Test matches in the same way, they tend to get tedious after a short while. It's a poor piece of equipment. Most respected commentators (including your likes of Athers and Nasser) have long been of the view that Test cricket is at its best when the elements are *slightly* in favour of the bowling side and I wholeheartedly agree with them. Look at the 2005 Ashes for the obvious example where that applied, no huge totals, everyone who made a century properly had to work at it, technical flaws shown up and some superb bowling on show from both teams.
Meanwhile at Edgbaston, Warks are 662/3 at lunch. Ed Barnard can't be too happy to have got out for 1!