I will say i prefer the less clunky styling of the Kisumu 2 to the original model, but that's about it.  Not all changes from the original seem to work for my feet.  I MUCH prefer the neoprene lining of the original to the suede lining of the K2.  When i bought the Kisumu (1) a few years ago, i was able to hit the ground running in them.  They were perfect from day one. Unfortunately, I have worn the treads bare on my original pair. The top strap (ankle) on the K2 is shorter than the orginal and the heel strap on the K2 fits much different than the original.  The thick suede strap lining is MUCH shorter and hits right in the middle of my heel as opposed to wrapping around my heel.  It rubs right in the achilles area causing a red spot.  I would probably return these had i not tried to break them in w/ a 3 mile walk yesterday.  Instead, i've spend a couple of hours this afternoon attempting to stretch the heel strap slightly and really trying to soften the thick piece of 'lining' on that strap.  Though i don't miss the neoprene 'gusset' under the toe strap, i sure wish at least the ankle and heel area of the K2 was neoprene lined like the original. Am really hoping my 'modifications' will work, but i'll still be breaking these in s l o w l y.  I would buy another pair of the originals in a hearbeat if I could find them in my size :(