In reply to Andy Cloquet:
Not of the mid version, but I've just bought a pair of the shoes though. Only took them out for a test stroll today. My main concern was the fit but they felt good enough around the house and on the stairs that I decided it was fine to get them dirty.
I've had a pair of TX4 mids for a couple of years and have been perfectly happy with them. Got the Boulder X's on the strength of that (they were cheaper than the low version of the TX4s too).