Mid-way into my weekly commute update:

The IRC Metros are holding up nicely! I rolled over a hunk of broken bottle, heard the bits of broken glass make crunching sounds under the tire, but no punctures, no cuts, no embedded stuff. I made several various-sized rocks ricochet from under the tire with no damage to the tread or sidewall. Tomorrow has rain in the forecast, so I'll get to see how the IRCs handle wet corners as well as wet road debris.