I have an '85 Ibanez Roadstar II 5 string, the first 5 string Ibanez ever made. The distance between the center of each string to its neighbor is 15mm. Ibanez took their 4 string Roadstar II neck, body, and pickups, designed a new headstock, and put five strings on it and baschta.
In the opposite direction, my highly modern, stylized Spector Rex Brown 5 has a spacing of 18 from center to center and a wider neck and wacky string tension.
A world of difference between the two.
I think the Ibanez SR 5 string bass is the most comfortable on the planet (that you can just buy at your local Guitar Satan or something). I understand Ibanez isn't for everyone (and my opinion of them might be a little biased

), but I think it's a pretty good middle point. Very confy as well. And they don't have to be expensive to be worth your money.