After much research I finally opted for Bontrager Jones XR 29" tyre for my new 29" uni.
http://www.bontrager.com/Mountain/Wheelworks/Tires/5795_popup.php
It’s excellent and just what I had hoped for. It’s 2.25" wide so it’s got good volume for the bumps and hopping. There’s actually not much difference in volume to the Big Apple, it looks about the same but it does have knobbles which tend to make the tyre look bigger.
It has a non-aggresive knobbly tread, the centre ones are low and give an efficient ride, on tarmac it rides straight and true and completely eliminates the sideways drift on a camber which was my main aim and a problem with the BA and all other knobblies I’ve tried. The side tread is knobbly enough for off-road and mud.
It’s also very light, only 600g, so that’s a 300g saving over the BA and coupled with a KH rim gives a very light and responsive 29 xc machine.