Improve your schedule. 

Noise can be a real problem for your rehearsal schedule. If you're living in an apartment or your concrete basement is sending bass waves flying into your neighbor's kitchen after work, you may find the cops knocking on your door letting you know that not everyone appreciates the dulcet tones of your genius. You can drop your PA, amplifiers, and acoustic drum kit entirely with today's incredible electric and emulation options for full-on silent rehearsal, or you can eliminate one or two of your sound sources to drop the volume and maintain the peace.

Improve your tone.

Sonic space is limited. You can only cram so much into the human ear, and we all know what a bummer it is to put 2 guitars and a bass on stage only to throw mud at the audience. By removing the room from the equation in your rehearsals, you and your bandmates can more effectively analyse exactly where your tone sits in relation to everyone else. When you do some serious critical listening, you can spread the band out sonically, making your tone ring through on even the dingiest stages. 

Improve your muscle memory.

They say that practice makes perfect, but we know there's more to it than that. When you practice, you develop muscle memory, and if you practice wrong, you'll develop bad habits. By rehearsing in a sonic environment that is free from the bouncing artifacts of a typical concrete practice space, you help your ear and your hands coordinate for proper placement, strike, and mojo. Practice doesn't make perfect. Perfect practice does.