It was canned a while back due to problems experienced by users. But thankfully all of that is behind HTC and its rollout of KitKat to the HTC One and One Max.Interesting timing too. With the new HTC One launching, the old version(s) will be running the same operating system, so perhaps less of a need to upgrade straight away.It's available via the software update button on your HTC phone if you have a handset with Vodafone, O2, Three or a SIM-free model. EE customers will have to wait just a little longer. No doubt still doing a spot of testing. If it's not there, keep checking, it's probably a gradual rollout.What HTC doesn't offer is an upgrade to Sense 6 sadly, you'll still be on Sense 5.5 for the UI. it also doesn't offer the Home launcher feature, but it does offer a transparent notifications bar, Google Hangouts, native printing support and we would expect, all-round better performance for your phone, with 4.4 being more memory efficient.Worth the upgrade, but not a massive step forward.