In my TL, function remains unchanged from iOS 6. No metadata shows. Acura never issued an update and simply updated to their page to say iPhone 5 and iPhone 4S with iOS 6 has limited capabilities in that song titles and data connection aren't available.
My battery life on my iPhone 5 was abysmal prior to the update. I had my battery swapped out a few days after the update and things are back to normal. I was looking at comparisons from my iPhone 5 when I first got it last year, and battery life isn't quite as good as then, with difference being marginally degraded for me over the course of the day, in comparison. My numbers show that in general, for various usage cases (time used / time on battery), I drain <2%/hour more than on iOS 6 when the phone was new for higher usage cases, and about the same in low use cases (think, phone mostly idle).
Of course it's not so cut and dry comparison, as my numbers reflect simply "usage" time versus "standby" time and not a realy testament to how I'm using my phone (watching a video versus browsing the web, versus playing a game) or what the signal levels are like. These are more simplistic numbers of just how I "mostly" use my phone when I'm barely using it versus moderately using it, versus heavily using it. Thes scenarios tend to always be mostly the same for me (a heavy day means I was tethering, a light day means I was home pretty much all day, on Wi-Fi, in a good signal area, and rarely using my phone for more than a quick mail check, facebook check, or SMS/iMessage). I'm a bit of a dork and collect data like this, specifically so I can compare and reference when there is an update or I think something isn't right.
That's just my experience. YMMV.