Many years back I was told by a teacher to find one bass to practice on rather than switch between several different ones. Even at that time (over 25+ yrs ago) I owned several Basses. My teacher at the time told me that switching my practice sessions over different neck designs would complicate my feel for many things. I had a different idea: in that it would allow me to adjust to different "feels" and would benefit me. However I took his advice as that was what I was paying for. What's your opinion? Do you spread your practice over several different instruments or do you have one special "practice" instrument and what has been the results?