Can't sync music on iPhone 6 with iOS 8.1 and iTunes 12.0.1.26 on Windows 8.1

As far as I know I have the latest of everything. I have tried:

Syncing over wifi with the cable disconnected from the PC

Syncing over cable with airplane mode on (thus no wifi)

Resetting my phone

Manually managing music

Wiping all music and starting over

Toggling music sync on and off

Uninstalling and reinstalling iTunes

Problems are all over the place:

1) Sometimes it will copy like 100-200 songs and then act as though the iPod got disconnected and reconnected.

2) Sometimes it will hang on "waiting for changes to be applied"

3) Sometimes it will complain that files are not the right format, but then it will copy them over fine the next time.

4) Sometimes it will stop and say "unknown errors"

It's really hard to troubleshoot because of how all over the map the problems are. Before updating to iOS 8.1 it would at least sometimes do a solid run of almost 500 songs before malfunctioning. Now these problems are much more frequent.

I never had these problems on my iPod and older versions of iTunes. I know the iTunes version for Windows is an afterthought, but given how expensive the products are it should work as advertised. iTunes is by far the most buggy software on my system, everything else works well so I know there's nothing wrong on the OS level.

At this rate I'm probably going to just go to a third party solution. I have a subsonic server set up so I can just download my music through there into an app's cache, like iSub or something like that. But it ***** to have to rely on cumbersome third party software for things that are advertised to work out of the box on these $800 devices. I am a developer during work hours, I can't imagine what this must be like for non-technical people who bought the these products thinking it was going to be as simple and intuitive as they advertise their products to be.