Marshall claims that this iconic amp was used by Billy Gibbons of ZZ Top

Joe says in a Gear Gods interview, "The very first amp I used was a Valvestate Marshall. You know, I liked those amps. They’re very precise and sharp. The low end is very transistor." Then later mentions, "Yeah, those are what Meshuggah used to use way back in the ‘90s. I saw Meshuggah back in 1998 and they were using those Valvestates."

The Empty Words Project is founded by Chuck's family. Here they republish an interview with Pit Magazine, originally published in June/1999, Chuck Said: "My amp is a Marshall Valvestate head and cabinet, that's about it. I don't use effects except for a little chorus on my leads, I really like a basic setup." This article from Guitar Geek confirms this as an 8100 specifically.

In this video, Ola Englund uses a Marshall Valvestate amp head with his Hesu 2x12 cab.

In this post, on Sum 41's Facebook, the caption reads, "just bought these new amps. these 2 amps together make such a huge sound. this is what we used a lot on the chuck album. they were the main guitar sounds on "no reason" "bitter end" "angels with dirty faces" and "we're all to blame". i can't wait to lay some guitars down for the new record with these. you'll hear a lot of them on this new stuff. "

A marshall vs8100 head is visible in the studio during the recording of The Bleeding in part 1 of the centuries of torment documentary/video (https://youtu.be/aGPot3rP53o) at around 1:28:57.

Producer Ulrich Wild states that Wayne's guitar parts for Wisconsin Death Trip were recorded on a Marshall Valvestate 8100 in this video

"I used a Marshall® Valvestate 100 watt head going through a model 1960A cabinet with Celestion® Vintage 30s in it, and that was killer. For effects, I used a Digitech® Whammy, an old Ibanez® chorus, and I also used a Line 6® Pod Pro for a lot of my effects as well because it has a wide variety of effects that I really like."

In a 1997 live performance video from the "Anthems to the Welkin at Dusk" tour in Milan, Ihsahn of Emperor is seen using the Marshall Valvestate 8100 guitar amplifier head, identifiable by its prominent logo and gold panel.

Linde used an amp that appears to be a Valvestate in the mid-to-late 90's.

Vogg used it to record the Nihility album

He used valvestate amp on live gig.