The solid bass string will have the traditional "twang" that is commonly referred to as "silvery". The wound strings are generally fuller toned, what I liken to guitar sounding. It all boils down to personal preference.....

I play noter drone.

Drone or chording?

For me, the gauge remains the same.

Is the plain string the same gauge or a different gauge from the wound string?

It eliminates most of that awful sound the bass strings makes when the finger slides up or down the string.  The tuning does not change.

I remember seeing some comments about using a plain string for the bass rather than a wound string.

Can anyone offer some enlightenment about why and also what tuning you use when you use the plain string?