I took a sampling across the six-pack of the 2000 vs 2015 remasters. The sampling I took was the songs from the current tour. I compared a few points in each song side by side. Here's what I heard:

Subtly better. The reverb is tightened up a touch, and the bass guitar is more audible. I could hear no difference in EVH's or DLR's parts. The drums have only barely perceptible differences. The biggest difference is the sound of the bass guitar, but even that is not a game changer. Not worth buying again if you have the 2000 remasters.

Oh, and I hear a weird noise in the 2015 Hot For Teacher. There was already hum in the recording and it sounds like the remaster turned that steady hum into a throbbing hum. I don't like it. Could be my setup.

Note: I'm not a super-hear-o. I'm not one of those people who can hear the difference between lossless and mp3. I'm not a person who can hear the difference between a guitar with brass saddles and steel saddles. So, take it for what it's worth...nuthin'.