Well, *now* I'm ******.
After updating my iPhone 4S to iOS 6 without any problem, I had this iTunes Match problem appear (artists, albums, and songs appear in the Music app, but without song titles and times 0:00, and nothing would play). I followed the iExplorer technique, and that resolved the Match problem (I was able to see my songs with the correct times, and download & play them).
This morning was the first time I connected my iPhone to iTunes since doing all that, and iTunes gave me the message that I needed either to set up my iPhone as a new device, or restore it. I tried the trick mentioned above -- selecting "new phone" then disconnecting the device before the setup sync started -- but that didn't seem to work. So then I selected "restore" and waiting about 20 minutes while the restore occurred. iTunes reported that, after the restore was complete, the iPhone would restart in its cradle, iTunes would find it, and the restore would be finished.
When iTunes didn't find the iPhone, I removed it from the cradle and discovered that it was off. I powered it on and waited, and it turned itself off after the Apple logo displayed for about a minute. It did that over and over again. Eventually I had to enter Recovery Mode, connect to iTunes, and start the 'new phone --> restore backup' process, which is running now.
I don't know if the restore will "stick" this time, but *now* I am highly aggitated about this problem. The Match-fix process wasn't that big of a deal, and it didn't take too long, so I didn't sweat it; however, now I'm sitting in my office unable to use my iPhone because I need to restore it for the second time (so far), all because Apple released an iOS update that ISN'T COMPATIBLE WITH ITS OWN iTUNES MATCH SERVICE ON ITS OWN DEVICES! Had Apple bothered to warn us that its iOS update would screw up our iDevices like this, I would've seriously considered whether or not I wanted to go through this aggravation.
And all of this after I was preaching to a group of people about how the iPhone "just works", without the headaches that seem to plague Android phones. <shaking my head>