I currently only have one 5 string, and the other 6 I own are all 4's. I used to just swap whenever I felt like it, and take whatever bass I thought appropriate for the gig, but after being on a cruise ship for 2 and a half months, reading and playing nothing but my SR5, I'm finding playing a 4 again a little weird! When I first picked up the five there was literally no transition period, it was just a 4 string with some extra notes to me rather than a different kind of bass, and I could pick up one or the other without thinking. Now I feel like I've got so intimately acquainted with the 5, that I'm picking that up over any of my 4's, and it used to be the other way round!