Tempted to do the same. The Sony forums are overwhelmed with posts from Z3/Z3C owners complaining about a multitude of faults from the update. The major concern is the battery drain. One of the main selling points of the Z3/Z3C is it's godlike battery so I'm hesitant to upgrade if it's going to lead me to be forced to charge it every night. I bought the Z3C to evade that.
As for Lollipop it's becoming tiresome waiting for it. So many other manufacturers have already issued the update and Sony is taking forever. I still believe they produce wonderful and beautifully engineered phones but their software support is dire. The Sony site states that Lollipop is available now and yet it's not. They haven't even announced a firm release window yet.
"Next week or possibly the week after" is all you can find if you research it. Anyone know anything I'm missing?
I was thinking that the Sony had to have halted the rollout to work on these issues that people are reporting. I was assuming that a lot of the UK/US haven't received this. But then I thought if that's the case, then why would have announced they are rolling out the update to the Z2?
http://www.xperiablog.net/2015/04/07/xperia-z2-rollout-widens-to-include-hspa-d6502-model/
I just don't get it Sony...
EDIT: http://forum.xda-developers.com/showpost.php?p=59850372&postcount=518
^ This post seems to be pretty positive. Maybe I'll just remove my SD card and factory reset my phone before applying the update..