Been thinking ubass. since you really have to plug the hollow body in for anything but practice, any advantage over the new solid body ubass, they both seem to be about 400 or less. the solid body sure look cooler.
I'm not much of a bass player (yet)...that said, I've been very tempted to pick one up as well and have had the chance to play a few side by side.
They are very, very similar but not identical. The hollow body has slightly less sustain, slightly sharper attack. Think slightly closer to an upright bass. -Although honestly, with the strings these things use it's really difficult to get any real attack out of either of them. The hollow body also responded stronger to slapping, etc since it picked up a lot of sound from the top that just vanishes on the solid.
All and all the hollow body can get a thump, thump attack/tone better and easier then the solid. The solid is smoother and thicker/fatter tone by contrast. Again, these differences are incredibly small and don't go thinking the hollow body will ever be able to pretend to be an upright with gut strings, despite all the comments about "how much it sounds like an upright" it honestly doesn't. No one is going to be playing rock-a-billy or trad jazz on this thing anytime soon. It has its own sound, farther from a guitar then an upright, but still no where near either.
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For myself, I was leaning towards the hollow...but I'd want to use it for a super-portable bass to play 20s-40s music and I think it'll just be too clean sounding and ultimately disappoint. So now I'm leaning towards the solid...if the sound is going to be super clean and fat anyway, I might as well go whole hog and use it for contemporary music (plus, I agree, the solid bodies look much better).