If you're really set on either the 2400 or Kanga, here's a quick breakdown (since I've got both):
Differences:
The 2400 has a 40MHz bus, the processor (180 or 240MHz) is on a replaceable daughter card (for upgrades up to 400MHz), it can easily support CardBus via a simple hardware hack, has a max of 112MB RAM (with special 96MB SO-DIMM), and it's very light.
The Kanga has a 50MHz bus, with a soldered 250MHz processor, CardBus functionality requires mangling/replacing the soldered PC card cage (same with the 3400), it has removable expansion drives, and supports 144MB RAM. It weighs about 7 or 8 pounds and is quite thick, partly due to its 4-speaker audio setup.
Similarities:
Both are rather difficult to find relative to their peers/replacements (3400/WallStreet). The 2400's G3 processor upgrades are often prohibitively expensive; even the 240MHz variety can exceed >$200. Both have essentially the same graphics system, a Chips 655xx-series, with 2MB of dedicated VRAM. Both machines have 800x600 LCDs, though the 2400's 10" display is obviously smaller than the Kanga's 12" display; I prefer the 2400 here, as its picture is much sharper.
Both can run OS X 10.2.6 reliably and fairly pain-free via XPostFacto, provided the machines are flush with RAM. They don't support sleep or display brightness adjustment under any flavor of OS X, though, as the PMU isn't properly supported.
Differences:
The 2400 has a 40MHz bus, the processor (180 or 240MHz) is on a replaceable daughter card (for upgrades up to 400MHz), it can easily support CardBus via a simple hardware hack, has a max of 112MB RAM (with special 96MB SO-DIMM), and it's very light.
The Kanga has a 50MHz bus, with a soldered 250MHz processor, CardBus functionality requires mangling/replacing the soldered PC card cage (same with the 3400), it has removable expansion drives, and supports 144MB RAM. It weighs about 7 or 8 pounds and is quite thick, partly due to its 4-speaker audio setup.
Similarities:
Both are rather difficult to find relative to their peers/replacements (3400/WallStreet). The 2400's G3 processor upgrades are often prohibitively expensive; even the 240MHz variety can exceed >$200. Both have essentially the same graphics system, a Chips 655xx-series, with 2MB of dedicated VRAM. Both machines have 800x600 LCDs, though the 2400's 10" display is obviously smaller than the Kanga's 12" display; I prefer the 2400 here, as its picture is much sharper.
Both can run OS X 10.2.6 reliably and fairly pain-free via XPostFacto, provided the machines are flush with RAM. They don't support sleep or display brightness adjustment under any flavor of OS X, though, as the PMU isn't properly supported.