In June 2016, Mastodon guitarist Bill Kelliher made the switch from being a longtime Gibson player to being an endorser of ESP Guitars. The manufacturer made Kelliher his own signature model through both ESP and LTD, and now Kelliher has explained to Ultimate Guitar that he made the switch because "I never really felt like I was accepted at Gibson" and that he felt like Gibson didn't care about him as a player.
I never really felt like I was accepted at Gibson. The communication over there is terrible. They kept fucking up my guitars that I was asking for. I didn’t ask for a lot – I just had a few certain things that I would like with my guitar – I told them I didn’t want it chambered and they made my second guitar chambered. All the guys I worked with over there – the A&R guys were getting fired left and right and the company just seemed to be falling apart to me. There were new guys who would come in and they didn’t know shit.
It was a breath of fresh air working with ESP. They were interested and would ask me what gauge strings I played and what tunings I play – Gibson never cared about any of that stuff. Kids would get my guitar in the mail and ask me how to tune it because it wasn’t tuned and then I would tell them how to tune it and they would say it still doesn’t sound right and it’s because they’re not putting my gauge strings on there. They weren’t even tuning the guitars to my settings or specifications – just little things like that. Things that make the guitar a Bill Kelliher model, like put it in my tuning so that when it shows up, it’s different.
Kelliher also cites Metallica's James Hetfield as another big name guitarist that moved from Gibson to ESP, and "it seems like there are a lot of bad decisions being made over there." Later on in the interview, Kelliher says his signature Gibson guitar was a hit in terms of sales, but after the guitars sold out, Gibson turned around and told Kelliher they didn't need him anymore.
"We sold every guitar that I designed – both types, and I did everything they ever asked me to do. And they were just like, 'Eh, we don't need you anymore.' So it was like, 'Fuck you guys.' I mean, I did every clinic and anything they ever asked me to do. I don't know why, but they treat their artists like shit, basically. ESP doesn't."
So it seems safe to say that Kelliher is probably going to stick with ESP.