I feel more at home on a 6 string, so I play one as much as possible.
With the cover band, we go from Eb standard tuning, to playing in drop C#... So I just use a 4 string and drop the bottom string up and down so that I don't need an extra bass (drop tunings are too weird with an extra string below it!)
I've got a 5 string, but strangely it confuses the hell out of me still