scooping the mids is absolutely the worst thing any guitarist can do to their tone! Think about it... what frequency range does the guitar cover..... wait for it..... THE MIDS! So, why on earth would anybody want to take their guitar out of the mix? That scooped sound you hear on a lot of metal albums takes place after the guitars have been recorded, and is done to the whole mix, and not just the guitars. The only time I would say that it would be acceptable to scoop your mids, would be if you were just playing by yourself just for fun. Otherwise, you should keep the mids boosted. Actually, for a guitar to sound huge, thick, and crushing in a mix, it usually doesn't sound all that great on it's on after you take away the bass, drums, and possibly a second guitar.