As much as I enjoyed my previous bike, a Foxy Mondraker, I began to REALLY notice the lack of front wheel traction and the additional work it took to keep the front end hooked up. And I decided, right or wrong, that it must have been caused by the long 490mm Reach (finally a bike that fits!) combined with the short 435mm chainstays. Hen I shopped for a replacement bike specifically to change that aspect and found success, and consistently faster rides, going to an S5 SJ Evo with 448mm chainstays.
It's still a confusing topic for me and there is no such thing as the perfect chainstay length (consider the wildly different body weight distribution between a female and a male for example; or the different weight distribution based on STA & seat height alone) but longer than typical for a size large bike is much closer imo.
BTW I did try the even longer chainstay length adjustment on my Evo but just couldn't quite get on with it. My shock seemed harsh when sag was set correctly & rear traction suffered.
Why does an adjustment in chainstay length through adjustable dropouts negatively effect leverage ratio? Can't you just increase spring pressure and end up at the same place?