I'm a fairly novice runner, really a cyclist that started trail running. I was running in either barefoot shoes (merrell trail gloves) for short runs or some heavy trail shoes (adidas thrashers) for longer sessions. The kinvaras nicely do the duty of both sets of shoes.

Pros:

Very lightweight
Enough padding for comfort on longer runs
Minimal drop, 4mm

Cons:

Sizing. They fit snug, you should probably go a half size up from your normal shoe. I did, but even then the toe box is pretty narrow if you've got wider feet like I do. If in doubt, try them on in a store.

Other than the sizing it's hard to find too much fault. They're a great all purpose shoe that will perform well on trails, road, short or long. They're now my only running shoe.