Strengths: As I have ankle/heel problems, the kayano 18 did really well for me & lasted for the best part of 2 years (around 1k miles), tho9ugh I didn't use them for trail running. The kayano 19s are lighter, but look & feel as good. Shorter laces which seem to remain tied.
Weaknesses: Pricey - but if they last 2 years like the 18s, they'll have been good value. I didn't like the original colours, but these are more like my 18s.
Overall: I couldn't get a replacement pair for my kayano 18s, so I felt I had to go for the 19s. I rated my last shoes very highly & these seem just as good.
'Used in mud, snow, rain on trail, brilliant support. Will replace with the same'
Strengths: Good grip in almost any conditions - including ice, heavy mud & wet grass. Brilliant lace-up system. I have 2 pairs just for ordinary use. They also support my perennially sore ankles/heels extremely well.
Weaknesses: I wouldn't want to use them for long road runs - a bit heavy & rigid (for my heels/ankles). I thought the fabric had tonr 3 months ago, but it seems to be only the outer layer. But after 3 years, often in atrocious conditions - mud/pouring rain/snow & ice - they've done OK
Overall: For a pronator with ankle/heel problems, these shoes have been fantastic for trail running - at least once a week, at least 8 miles. I've done trail half marathons in them - including through a blizzard & through snow & over ice. I will definitely be buying another pair for running - in addition to the 2 pairs I've got for everyday use.