So far, I'm not sure what's different.
My Lumia 1020 still has no battery usage info -- everything shows 0%.
There's 16 updates pending, 14 of which are showing "Error, see details". One of them that's downloading now is invisible... no icon, no name, just a progress bar. 19 minutes later it doess seem ot be retrying, and sometimes succeeding. Maybe it works when you stare at it, and only fails when the install completes while you're not on the screen. There's some sort of pattern here I can almost figure out.
Dead Apps that won't even try to download, that I have to delete: Mobile TV, Keeper, Device Help, AT&T Lockerl and those I cannot delete: Lumia Help+Tips, IE (these things are not Apps I bought or installed; they're on my phone after a reset to 8.1 and before I've picked anything myself to install -- I presume these are OEM-installed things that the Windows 10 Mobile upgrade needs to explicitly get rid of). And while the update attempt failed, at least they don't seem to reappear wanting to update, except for "Lumia Help+Tips" which always comes back and there's no entry in the app list from which to attempt to uninstall it.
General scrolling is still jumpy. It'll go smoothly for a half or more of screen length, then jump a half screen such that I have to scroll back or I've missed things. It's smooth when it does scroll; there's just these jumps, and for the start screen they were always sort of in the same place, and it feels like it's the same now, but once I have more apps installed and pinned to the start screen I'll have a better idea.
"My Library" in the Store still takes a couple minutes to show all apps I own so I can pick what to download again.
No "Loading..." loop so far. That's good. But it wasn't an every-time thing anyway, so we'll see.
Outlook crashed the first time going in to sync setting changes for an Exchange account and selecting a checkbox.
Hopefully there's some improvements hidden in this build.