Have posted about these several times, but having owned three pair, will do so again.
The first two pair each lasted about a year of day hiking and spring and summer trekking (would love to be out there all summer, but cannot afford it and there are commitments - so a trek for me is usually the better part of a month) After getting thoroughly sopped a few times, the outsoles started to come apart (they are made of different pieces bonded together), and the uppers started to separate around the bottom edges from the soles, allowing rain to enter.
The third pair had the worst adhesion of all, even when brand new, as the tops of the sole could be easily peeled away from the leather. So even before using them, PU glue was worked between the sole and the leather around the boot with a shaved popsicle stick, with the excess cleaned up with Isopropyl alcohol. Doing this when new worked great, and has prevented the separation experienced with the first two pair; but the third pair has yet to see a trek of several weeks, with the usual days of rain and slogging that will bring. The PU glue treatment is also not going to help the sole pieces hold together any better.
Wrote to Keen a few years ago about all of this, and got no reponse, even though pains were taken to be 'fair and balanced'. They did come out with the Gypsum, which is also billed as a 'mid', but is about an inch higher. If you like the feeling of freedom that a true 'mid' allows over a hiking boot, the Gypsum will probably be a disappointment. Too bad, because it appears to be much better made than the Targhees, and would be just as light, perhaps moreso if it were the same height. In it, the foot is closer to the ground, giving me a feeling of more control.
Won't say much about the fit, because that is different for every individual. The purchase of three pair despite the shortcomings was due to the comfort on the trail. Many boots fit OK in the store, or on a flat surface, but most fall down and begin to hurt when negotiating the rocks and roots of the White Mountains (By then you can't take the boots back). At least I could get through long treks comfortably in this boot, unlike most others.
Have noticed that each pair had a little more volume than the prior and required more shimming for the smaller foot; and that, along with the durability issues, has driven me this fall to try a slew of other mids to see if something better could be found. Unfortunately, I use a prescription orthotic that needs a flat surface underneath it to work; so narrow-heeled mids with some arch built in, like many Salomons and LaSportivas, do not work - the orthotic rocks over the arch. Otherwise, the search would probably be over already.
There is also the weight issue. The Danner Radical 452 is an excellent boot for me, and far more rugged then the Keens but a pair are a pound heavier than Keens. That pound really makes a difference, especially on a longer trek, or even a longer day if I happen to screw up the navigation.
The Targhee's sole is IMO about average for grip. But that can mean longer wear, except for the separation of the sole parts. Reach for the MicroSpikes on icy surfaces though. I do everything conceivable to avoid wet mossy rock, so that has so far not been a problem. But there is a lot of poking about and carefull treking pole planting with the Targhees, especially on rocky descents.
Despite all the above drawbacks, I will probably use the Targhees most of next year because of the comfort, and then throw them out like the last two pair. They get so ratty that a hunter I ran into in Colorado got a good laugh looking at the second pair. I have a pair of discontinued Garmonts on order, as well as a new pair of 452's for day hiking in the Whites, and if an equally comfortable yet more durable alternative is found will certainly post it with an update on my 'Duckfoot' thread from a while back.
Good Hiking to all, whatever is on your feet.