Inov-8 Roclite 390 GTX

I've been using these boots 4 times a week for about a month, for a mix of fell/hill jogging and fast, double-time walking. There are both plus and minus points to them:

Plus points -
1. Obviously very, very light.
2. Comfortable around the foot (no blistering or rubbing).
3. Underfoot comfort is probably going to depend on your foot type, gait, etc, but for me was a nice balance of support and cushioning. I've had surgery on both knees, and have had no problems so far.
4. Can be worn for walking or running.
5. Good levels of grip on a variety of terrains.

Minus points -
1. Be warned: these are NOT waterproof boots. Several other people have mentioned this in user reviews on various sites. I have walked on short, damp grass and ended up with wet sock soles.
2. The leather around the heels is pretty thin and flimsy. Anyone who walks over scree is going to chop lumps out of it very quickly.

Overall - comfortable, light, well-cushioned, decent on mixed terrain, but not waterproof, and probably won't last that long.