1. The Lumia 920 does not have an SD slot.
2. I have 16.92 GB of music on my device (according to the phone).
3. Comparing wedding DJ music to my music isn't the best of moves. I'm guessing that music is almost entirely popular music that Xbox Music has in its library and has been on the radio over the years and so on. However, I have probably 5-10 artists in my library that likely aren't on Xbox Music, and that gives it a fit, as it'll try to turn that music into a something else if I don't stop it.
4. My music tagging issues are 100% the fault of Xbox Music. If I'm not on their "cloud," I'm 100% fine. It never had a problem on my Zune. It never had a problem on the Zune software. MusicBee handled it perfectly. My Droid Incredible had no issue. My device on GDR3 had no problem with it. My device on 8.1 has no issue, once I get it off of "the cloud."
5. You misread my statement. I never said that the OS should be in the garbage, I'm saying the way I use the OS is begin put in the garbage by these changes. If I break down my device usage, it's probably about like this:
60% Music
10% Games
10% Texting
8% Internet Searching
7% Internet Browsing
4% Calling
1% Other
The 8.1 update has made my experience with music, games, and Internet searching worse. That covers 78% of my device usage (very rough estimates). The texting's POTENTIALLY better (depends on how I adjust to the idea of swipe-based texting), so maybe 10% of my usage is improved. The rest is untouched, or 12%. So, if 78% is worse, 12% is unchanged, and 10% is MAYBE better, then the best-case scenario (if we weight this all evenly) would have the device at 68% worse.
Regardless, you decide to deal solely in absolutes, where as I do not. I've said that this ARE problems, and that the update IS bad. I've not said that they will ALWAYS be problems, or that this will ALWAYS be bad. It's the same thing as with the Xbox One. I made it clear that in its original state, I wasn't touching it. Everyone took that as my saying that I'd never get a One, but when it improved, I got it. As I said, if I had the chance, I'd be back on GDR3. I won't recommend updating the device to anyone I know. If it improves, then my opinion will change. However, I'm not going to make my opinion on the present based on an unforeseeable future.
So, as it stands, this update IS bad. It might not be bad when it officially releases, but I'm not going to say that the update is good now because it might be good later, given that we have 0 information on what will be changed by release. I mean, you obviously give them time, but when you take something that's good for 18 months and break it, it's hard to say "sure, I'll wait 6 more months to get what I had before."