The shifts aren't a big deal to me. What I will concede is it's nice to have the low Eb and D. Beyond that, I don't really care about the notes below them. For my ear and equipment, they are largely unusable.
On a practical, mechanical level, the interchangeability of bodies and and necks among fours is substantial. Fivers are far more proprietary in nature. Because of all this, all things being equal, I'll probably choose a four.
Absolutely. That is why I stick with the 4. I never used anything below the D...which I would like to have. Not enough to use a 5 all the time.
I tried the hipshot but could never get it to tune right. I'm sure it was me and not the machine.