I love the SM7B - and working with a lot of male rap vocals - for this role its pretty much my number 1 goto mic... Like everyone says, it does need a fair amount of gain (being a dynamic mic) but for anyone looking to buy a mic with a budget for a cheap condenser or one of these - i'd definitely recommend checking one out.. the build quality is far superior to most of the modern chinese LDC and the sound is rarely not suitable, sometimes outstanding but always useable and the mic responds well to further processing without any detrimental side effects. When tracking a band live with everyone in one room, the amount of off axis rejection of sound is often good enough that if a guide vocal turns out to be a one take wonder/performance of a lifetime (you get the drift -lol) then any spill recorded wouldn't really be a problem.. Its other main uses for me have been as a good kick drum mic (never tried it on snare) - less EQ'd/hyped sounding than a AKG D112 or Audix D6 in this role and on guitar cabs where it kicks some major butt (coupled with a thick tube pre its phreaking awesome!! The UA LA610 and this mic is a winner 99% of the time)
Overall - its like another studio workhorse of mine the AT4050, a solid performer - rarely the wrong tool for the job, but sometimes the perfect one.. and neutral enough to take further processing in its stride.. You DO need a pre capable of a healthy amount of clean gain (of which there are some great ones out there that won't break the bank - like my new fave the TK Audio DP-1
) but this is an example of a worldclass dynamic mic that keeps up mics 2 or 3 times its price in quality..