Really comfortable, as I expected...but they squeak...with every step...both of them. Must just be mind since I don't see it in the reviews.
Also, I'm not a runner, I just wear these as regular shoes so the mesh to can be annoying when it's raining or in the cold.

2 month Update:Still 'technically' comfortable. I would still buy Boost shoes again. However, this model or this brand has become very uncomfortable. They still squeak and they have days, for lack of a better way to describe it, feel like they're not broken in yet. Almost like something is wrong with them.  I usually wear shoes for a few years. I've only had these a few months I'd I'm already looking to replace them. I'd return them if it was worth the effort.