I've been in 2 originals bands for something like 5 years now. I have 5 Ricks that are all set up very differently,a P,a J,a fretless,an 8-string,a Yamaha bb,and a Guild SB. (Hmmm,missing a hollowbody!)
I like to rotate them all (mostly) equally, just to hear how the differences in sound might affect the group sound. I typically only take one bass to practice,so if i choose the fretless,or the 8 string,every song gets that treatment that night. Fortunately,i've learned how to de-accentuate the overt characteristics of those,so every song isn't all mwahy or guitartwang when i choose them.