Massive perhaps... but also tight and articulate? That's gotta be there too. My gold standard as a soundman is that I shouldn't have to sacrifice one instrument for another. I want everything to be heard! The most common thing I see in those situations is the bass guitar being sacrificed for the guitars, because the guitars are invading the bass guitar's frequency range. Now maybe I'm a little old fashioned here; I grew up on Sabbath and Maiden and I want to hear EVERY NOTE the bass player is playing. He's playing a musical part, not just making the bottom end fuller. Ever been to a Maiden gig? It's an education if you ever do live sound. You'll be in a sports arena which is the worst sounding room on the planet, there are three guitars and a backstage keyboardist and I can hear the bass notes. This is partly because all of the instruments stay in their own sonic territory, partly because they have one HELL of a sound engineer, and partly because Harris and his bass techs know better than to sacrifice articulation for thunder when dialing his tone.
The other big issue is multiple guitars, and this applies even to metal bands tuned all the way up. You get two guys trying for exactly the same super-aggressive chunky massive sound and it's almost impossible to keep them separate in the mix. I saw Queensryche a few months back in a pretty good sounding room with an excellent perma-mounted line array, and I thought their engineer did a very good job. But the guitar players had almost identical tones and guess what... whichever guitarist was playing the least important part was basically inaudible all the time unless somebody was taking a solo. The soundman was obviously quite deliberately sacrificing one for the other just to keep the mix tight, and this should not be happening ever. It exacerbated tremendously if you have guitars tuned way down to the basement. It's harder to get articulation at lower frequencies even when you're NOT dealing with an instrument with too short a scale for it. I really wish guitarists who wanted to go that low would at least get baritone guitars.
Once again, articulation is everthing in a live mix, and as a soundman I'll sacrifice anything to get it. I'll brutalize your tone if that's what it takes to make you and your bandmates audible and clearly defined. If you have that massively downtuned thing going on you probably don't even wanna know how much I'm taking out of your lower mids just because I want every instrument articulate and audible and I WILL have it. On the other hand if you have a tone that sits well in the mix on it's own, I'll leave it alone even if it's a tone I don't like.