Hmm. I missed that the first time around Steve - personally I'd consider that an improvement. Not to sound like a broken record but I just don't like needless complexity in a tractor - especially if it removes an element of control. I assume the push button engage/disengage worked like most four-wheel-drive road vehicles - that is it worked well enough after a fashion, but at it's own pace, and you have to check some idiot light to tell if it appears to be in or out. A nice, simple mechancial and direct control that may provide some tactile feedback is all that is needed. Now if they only would have extended that philosophy to the PTO. (which they may have on the european model which has a two-speed PTO!)
Tim