Just as a comment: I am surprised how many people don't understand a bass with more than four strings. To me it just gives me more choices in finger positions.
I did have three six string basses but on learning that my nephew plays bass, he's at Oxford, I sent him my newest six. He loves it. I now have just my original fretted six in white and my natural Koa wood fretless. I found that the standard J size pickups installed on the bass were a bit weak on the outer two strings so I replaced them all with EMG soap bars. That solved the problem.
When I ordered the fretless that vast expanse of Ebony called a fingerboard scared me a bit so I had fret lines installed. The whole instrument is a dream to play!