I have a really bad feeling T-Mobile isn't going to update the S4 to lollipop just like they skipped over the S3 KitKat update.
Samsung's flagship from two years ago is next in line to get Android 5.0 and their flagship of the current year ( Note 4 ) still did not get any of that.
I am not speculating or anything i am a note 4 N910C(Exynos) owner Egypt version,installed the Poland lollipop 5.0.1 Rom and find it to be so lagy and full of bugs,rolled backed to 4.4.4.
And Xperia Z Devices are taking too much to be updated, this is really a shame. I only hope we can have a version without bugs it will be so disappointing if that happens after too much time waiting :(