I really like the new updates, both with the software and the firmware. My only complaint, with the firmware, involves the marketplace on the Zune. When viewing songs and albums there's no indication if the music you're browsing (and perhaps purchasing), is DRM-Free MP3s. I'll admit I don't buy much music from the marketplace, but for that reason alone I think I'll continue to use the PC software to make a majority of my digital audio purchases.
What issues are you having specifically? I haven't had any issues with my installation of Home Premium x64.