Is WP way behind? No. Does Android 5.0 have customisations beyond that which WP currently has? Yes. But simply being ultra configurable does not a great phone, make. Neither does having fancy transitions on tiny UI elements turn Android into some super advanced mobile platform. IMHO, WP excels far and above Android in part because it gets out of your way to enjoy the experience. The UI is still way more fluid, more integrated, more personal and no, I don't work for Microsoft.
I bought into the WP concept when it was officially announced way back in February 2010, having been completely disappointed with WM6.5.2. I love the Metro way of doing things. I love the deep use of beautiful typography rather than overuse of shiny bevels, gradients, textures, shadows. Android, if anything, is catching up with the modern UI language that Microsoft started way back with the Zune player. The technologies in lollipop are pretty much the same, with some incremental improvements in usability but more and more, I see the bombardment of endless settings everywhere as a hindrance, more than a help.
Sure, there are plenty of ways that WP can improve but eye-candy isn't one of them. Microsoft got that nailed from day one and everything since, makes using WP a pleasure and they've thankfully stuck to their guns and only improved in places where it has made sense.
For example, I feared that the addition of folders on the Start Screen would be a disaster and a clear break from the Live Tile experience. Microsoft completely blew me away. The combination of folders and Live Tiles just works and is a breath of fresh (again) against the static and rather PC-like folder implementation that Android employs. The Android UI is still trying to "add polish" as described in the video, meaning, it's been a complete mess to date and is now an afterthought.
I'm always asking my Android friends, does your phone *really* make you smile as you use it every day? Mine does.