I haven't seen the Ibanez 8-string. Is that 2 lower strings? A Universe 7 is already encroaching, you know! :-)
Joe Veillette (previously of Veillette-Citron and partnered with Stuart Spector on and off) makes a lot of baritones at his current shop. He has longer scaled ones (28) which are tuned a fourth below a regular guitar, sort of like a 6-string bass except for the 2nd string which is dropped a 1/2 step like a regular guitar. There are shorter ones too which are tuned down a step and high tension (less than 27 scale, so you barely notice the difference until you're down low on the neck).
As for attack, to my ears, instruments have a stronger attack when there's more tension on the strings. If you take a regular guitar and tune it in D instead of E with the same strings, then the tension drops and the sound is sort of floppier - less attack. Tune that guitar to F# and there will be a lot more tension and snap to the sound (hopefully that E string won't poke you in the eye when it breaks).
If you put a normal set of bass strings on a 30 bass, they will be very floppy and loose sounding relative to how they sounded on a 34 or 35 scale. If you crank it up an octave, those same string will snap, but if they didn't they'd be super tight. So, how a piccolo bass sounds and feels will be very dependent on exactly what you string it with and how you tune it. So, it could be either way, but I would guess in most cases people would be stringing a piccolo bass with strings that are heavier than the guitar strings that end up at the same tuning.
David Fung