The first table has so far proven to be accurate. Open diffs are cheap, reliable, and provide smooth highway performance, but can get you stuck easily on ice or sand, because power goes to the wheel on each axle that has the least traction. 4WD with open diffs means you can count on only 2 wheels to get any power, and they will be the ones on each axle that are slipping. Spools A spool is carrier setup that turns both wheels on an axle the same speed as the ring gear. But you can always count on power to both wheels.
Spools are common in drag racing.
Just take your open diff, and weld your spider gears to the carrier. I can't think of many situations where a spool would be a preferable modification to a Toyota 4x4, except maybe on a trail-only rig. This is a nice choice for people trucks that see a lot of pavement, but like to go off-highway once in a while and need a little help in the traction department. Limitied-slips give more traction than an open diff, but less than a locker or spool. The highway performance is like an open diff.