I used to own a zebra top T-Bass w/ 19mm spacing and it was incredible: killer tone and the action really couldn't get any lower! Unfortunately I had to sell it a couple of years ago, for emergency surgery for my dog (which was unsuccessful).
I can compare that T-bass with the current T-bass I have (older molder Vol/Pan/Tone/Thunderguts/flamed maple/17.5mm), and the newer zebra-top T-bass sounded much, much better. I ended up changing out the guts in the T-bass I have (Audere pre & Kent Armstrong custom pickups), and that made a HUGE difference: so much more authority in that bass now!