So I upgraded my unlocked red C6506 last night via the Sony PC Companion app and it was a pretty painless update. I usually hate vendor PC phone tools but the Sony one is very nice and has a few other features I plan to try out.
Anyway I now have my DashClock lockscreen widget back that I was missing from my Nexus 4. Sony's 4.2.2 implementation is very nice, I really like the ability to pick n' chose which "quick settings" show up in the notification panel and being able to put them in whatever order I choose.
My big fear with upgrading to 4.2.2 was regarding the Bluetooth stack - on my Nexus 4 there's a huge problem with Google's Bluetooth implementation where if I have my Pebble watch connected to the phone I can't reliably connect any of my Bluetooth headsets (Jawbone Era, Motorola S9 HD). I don't know if Sony is using their own BT stack or stock Android, but so far I'm not having any issues with Bluetooth on the ZL with 4.2.2, so that's a big relief.
I haven't spent a whole lot of time digging through the Settings menus but overall I haven't noticed too much else that's new. I did order a USB adaptor so I can hook up one of my PlayStation DualShock 3 controllers to the ZL, interested in seeing how that works. I also turned on the MyXperia device locator and tested it out, works perfectly.
One thing I'm having trouble with is figuring out how to set colors for the different calendars I have (Google, Exchange, HaxSync/FB Birthdays). HaxSync has its own setting and it seems to work on the Calendar widget, showing FB birthdays in blue, but when I go into the Calendar app those entries are the same color as Exchange (yellow). I can't find any color settings in the Calendar app itself. My Google calendar entries are showing up with a red tag. I'm sure this is somewhere obvious, if anyone can help out there I'd appreciate it.
Here are some 4.2.2 screenshots from my phone:
DashClock widget
DashClock widget expanded
Notification Panel with additional Quick Settings
Desktop showing transparent top/bottom panels