Windows 8 and music - how does it do?

Hi guys. Sorry to start a new post, but I looked through what is here and couldn't find an answer, so here's my question:

What is the Windows 8 Music app like with big libraries (60+GB)? I've used the OS, and I really like it, and I do realise I can just get iTunes, but I have a Windows Phone and I figured I'd give the MSFT route a try for once (I only really use Zune to sync right now as it gets sluggish on my machine).

Does the Music app cut it for you? Is it a worthy Zune/iTunes replacement?