Strengths: I am on my 7th or 8th pair of these trainers. I always have a different second pair and have been through brooks adrenaline, saucony mirage and omnis, asics 2160 and others but the Kayanos are always my favourites. I know that i a can put them on and run any distance or terrain and i will never get a blister or sore feet, in fact i have put a new pair on and ran a half marathon.
Weaknesses: Cant really think of any. They have possibly got a bit heavier as the models have moved on but not sure.
Overall: They are a great comfortable, supportive workhorse. They are also quite durable lasting longer than other models and makes i have used. They are also a great fit and have never rubbed or been uncomfortable
Strengths: Very light and encouraged me to run on toes rather than heels which is alot faster and gentler on my hips and back
Weaknesses: After about an hour my knee starts to get twitchy due to lack of cushioning
Overall: I was a very heavy heel stricker and was massively impressed with these shoes which had me naturally running more on my toes just through the way they are designed. However i cant run for more than an hour as my knees start hurting so i do longer runs in my Kayanos. I am still running more on my toes though.