Reamping is incredibly useful, though time consuming.
When possible I always try to get a DI signal from any electric instrument, be it bass, guitar og whatever just in case I feel at some point in the mix that the sound just doesnt cut it, or needs a little more size or whatever. The nice thing is that you keep the performance you captured while tracking and then you, as an engineer, can muck about with getting the best sound from your amp without wasting the clients time.
Stuff like trying out new microphone techniques and fiddling around with the amp level/preamp gain ratio to see how it affects the sound.
I use it very often on bass tracks, as our only good bass stack in studio is currently occupied elsewhere and bass players sometimes dont bring their own. Sometimes you also just need some gristle to that bass to get it to cut through a mix in certain places. We use a custom made, red-painted amp with three valves for this particular job, and it sound fantastically gritty
Anywhoo,
Re-amping is a blast.
