This is the first time I've done a review of some footwear, so bear with me. I managed to find these in a size 10 a few months ago, and so far I've walked about 100 miles in them all told. They weigh about a third of my previous Meindl boots - 390g as opposed to 900g per shoe, and I fully intend to take them on the HRP with me. They have proved to be really grippy, comfortable, breathable and provide support where needed.
The addage about 1lb on your foot being worth 5 in your bag, I really have found to be true. My feet are much less tired than they were in big leather boots at the end of the day. I have used regular Roclite 315's for day hikes for a year or so but am cautious about going without ankle support when carrying a heavy load without more training for my feet. Most sensible UL'ers warn against making the jump too soon, it takes a long time to build strength. Both Dave Wood and Steve Horner have written great articles about this issue, which show that its a journey and is rushed at our peril.
So, its no good me pretending I'm a runner and wearing flip flops to walk 600miles in, I'll hurt myself! The fact that these have ankle support works really well for a transitional hiker like me. They aren't heavy, but when my ankle does go over (which does happen occasionally on rocky terrain, anyone who tells you otherwise is plainly walking on water), it is fully encompassed and protected. Its happened a few times and I've been protected exactly as if I were wearing a 900g boot. These feel substantial enough in the toe area to stop bumps, more structured underfoot than my 315's, but still with loads of feedback from the ground so you can adjust your gait or walking style to the environment as you go.
They also don't have a goretex liner, so my feet are going to keep cool enough in the high temperatures of the Pyrenees. In the UK I have worn a goretex sock with them, a system which works OK, but I won't bother in the Pyrenees - if my feet are wet for a day or two, so be it, the rest of the time they won't be. The breathable mesh sits quite high on the boot, so most ground water doesn't get in anyway.
About the grip - these things are way more grippy than any boot I've used - the tread is really aggressive and sticky. To confirm that, I just wore Keen Targhee 2's on a very rainy 3 day backpack, and they were good until I got onto slick rock - after that, totally useless...even dangerous. (They also eventually soaked through, and then stayed soaked, thanks to that liner issue.) The 370's on the other hand, stick like glue on wet grass and mud, and pretty good on wet rock too - well almost. Don't go trying to use the middle part of your foot to walk on, say, the edge of a rock. That torsional system might help provide flexibility but it also has no tread. I did manage to forget that and skid quite badly once or twice.
The really brilliant thing about these is that they might be boots but they still allow my foot to bend. I really did start to walk in a different way. Descending from Dale Head in the Lake District with a big pack, normally I might have felt a few knee twinges by the time I got to the bottom. But I noticed that I began to use the ball of my foot - not heel striking, but using my toes - to take the strain, and this meant no knee pain at all. This is the way our feet were designed to work - look at where the hinges are! This, coming from big old leather boots, was a revelation. It means I'm less and less likely to use the middle part of the shoe to walk on anyway.
There is a caveat to that - my feet are still quite weak in the scheme of things, and I found I strained the instep of my right foot. I am quite flat footed and also over pronate, so need stronger, thicker insoles than the inov8 ones. I have since purchased Sole insoles and these seem to do the trick of supporting that instep. No bruising since, touch wood.
I really like these, I only wish Inov8 would make another unlined boot and buck the annoying goretex trend. I'll be starting my Pyrenees walk in these and hope they'll take me to the Med - they are showing early signs of wear on the sole but nothing too drastic. As on other inov8 shoes, the sole begins to impact a little, and on these, the more aggressive tread is ever so slightly worn now - but its minimal. If they don't get me all the way, I might be ready to use my Roclite 315's by the time I've walked a few hundred miles.