I bought one and I'm happy after 100 miles. I've got a bit of toe overlap which I seem to have on all the cyclocross bikes I tested. I'm enjoying riding around in the grass and taking a few shortcuts through the dirt.
With 23mm tires the bike feels almost as fast as my carbon road bike. I definately feel more vibration in my hands though. Can't feel any vibrations with the wider tires.
I seem to catch my shorts on the cables running on the top tube.
Feels similiar but not quite as snappy as a Specialized Crux which was my second choice. I would have bought the Crux but the Ion had fender mounts which is a plus for me.
The wheels seem durable. Hit a pothole at 21mph and 235lbs with 23mm tires hard enough to flat and bounce a water bottle out of its cage. There are a few mysterious noises coming from the bike now but the wheel is still true.