My one and only time seeing Van Halen live was at the Monster's of Rock Tour in 1988 at Candlestick Park (SF).
The band order was: Kingdom Come, Dokken, Metallica, Scorpions, Van Halen.
Van Halen was riding high with OU812, and without a doubt had the largest crowd, but Metallica figuratively stole the thunder. "Master of Puppets" had been out a couple years and "And Justice for All..." was going to be released a few months later. On top of that, they were a Bay Area band; this was like a home-game for them.
The Scorpions were the big losers. Squeezed between Metallica and Van Halen. The Scorpions quote hard rock unquote sound just wasn't built to follow Metallica and wasn't as grand as Van Halen. If they were following Dokken and leading into Van Halen, they would have been in a great spot, but the way it worked out, they came across as old and stale.
The biggest thing I remember from the Van Halen set was Michael Anthony had probably the worst Bass solo I've ever heard. I have no idea if he was drunk, stoned, or just sucks at solos.