The strings (I've put an "s" otherwise there only can be one, so good luck to measure the distance between one string ) spacing is only one part of the equation as mentioned earlier. I was mainly a 6 strings bass player and was feeling that 18 mm at the bridge with 9 mm at the nut and a 34 inches scale was perfect. I tried the longer scales up to 36 inches that I liked very much, but not my right shoulder (capsulitis). I can't play on shorter scale (< 34 inches).Then one day I bought a Yamaha John Patitucci II, with 19 mm strings spacing at the bridge and 35 inches scale and I simply wasn't able to play it, so I sold it even if I liked the sound : there is something in this bass that makes you struggle with it all the time and I'm quite tall with big hands (think wood cutter type).
The most strange part is that I now play 8 strings Extended Range Basses with 20 mm at the bridge, 9 mm at the nut and 34 inches scale, two Noguera basses (one fretless and one fretted). And I have absolutely no problem playing them : they are so easy to play just like my 6 strings 3/4 EUB...
My conclusion is that the lutherie and the ability of the luthier is certainly as important as the strings spacing and scale, or even more. The overall balance is really important too, just like the neck and body shape, without forgetting the weight.
So try as many as you can and find the one that suits you.