I know this post is a few months old, but I have been looking at getting this phone on an MTN contract. During my research, I managed to replicate a camera freeze bug on 3 different CellC in-store demo Z1 Compacts. Turns out that internationally, this bug is well known (along with a LOT of other problems) - all brought about by the 4.4.2 Kitkat update.
So be careful and research before updating. Apparently the 4.4.4 update fixes most issues (It is on Sony's website, but I cannot confirm if the update is rolled out OTA here in SA).
I know some people who have this phone on Vodacom, but they cannot replicate the issue, even with the same build number as the CellC phones I tested. So I'm wary of signing for a 2 year contract with a phone that gives me trouble from the start.
If there is anyone who can voice their two cents, please do. The iPhone is looking better and better at the moment :wtf:
Please follow this for more information regarding this issue:
http://talk.sonymobile.com/t5/Xperia-Z1-Compact/Xperia-Z1-Compact-camera-issue-freeze/td-p/651649