Theyre just rolling out the Lollipop upgrade now for my HTC M7 ( over here in Oz, last in the line as usual )
I'm not entirely sure I NEED this upgrade, will hold off until I see what it does - and more importantly how much of a download it is!
I have Samsung S4 with Kit Kat updated last year. Lollipop would be nice to have if Sprints allows updating. My phone is actually "half rooted" because I haven't finish Knox part although I disabled it anyway but unable to get free Hotspot working.
There are a few apps out there that can kind of change the interface, not sure on the system settings. I haven't tried it yet because I would rather have something to either revert the colors back to KitKat (ie the Settings background and anywhere where it's blinding white) or be allowed to have a choice of themes to have a better color palette.