Okay, I'll do it all again, except that I won't put the descriptions in, because that took the most amount of time.
Here we go (I'll be backing it up in notepad this time round...

)
Grass
% Kbot Speed Affected: Not Affected
% Vehicle Speed Affected: +20%
% Hovercraft Speed Affected: Not Affected
Hardness: Medium
Dirt (includes Mars type terrain)
% Kbot Speed Affected: Not affected
% Vehicle Speed Affected: +10%
% Hovercraft Speed Affected: Not affected
Hardness: Medium
Desert Sand
% Kbot Speed Affected: -10%
% Vehicle Speed Affected: - 20% (or 10% more than kbots)
% Hovercraft Speed Affected: Not Affected
Hardness: Very Soft
Snow
% Kbot Speed Affected: -20%
% Vehicle Speed Affected: - 30% (or 10% more than kbots)
% Hovercraft Speed Affected:
Hardness: Very Soft
Metal
% Kbot Speed Affected: Not affected
% Vehicle Speed Affected: +20%
% Hovercraft Speed Affected: Not affected
Hardness: Very hard
Marsh
% Kbot Speed Affected: -10%
% Vehicle Speed Affected: -40% (or 40% more than kbots)
% Hovercraft Speed Affected: Not affected.
Hardness: Soft
Archipelago/"beach sand"
% Kbot Speed Affected: Not Affected
% Vehicle Speed Affected: -10% (or 10% slower than kbots)
% Hovercraft Speed Affected: Not affected
Hardness: Soft
Roads
% Kbot Speed Affected: +10%
% Vehicle Speed Affected: +40% (0r 30% more than kbots)
% Hovercraft Speed Affected: Not affected
Hardness: Hard
Stone/Rock/Gravel
% Kbot Speed Affected: Not affected
% Vehicle Speed Affected: +10%
% Hovercraft Speed Affected: Not affected
Hardness: Very hard
moon
% Kbot Speed Affected: -10% (slower steps b/c of gravity)
% Vehicle Speed Affected: +10%
% Hovercraft Speed Affected: +10% (more efficient energy use b/c of gravity)
Hardness: Soft-Medium
I might have left a couple out; I hope not though. Feel free to disagree with whatever.
What I basically went for is that kbots are the kings off-the-road, and are really very good for all-terrain work. But in areas where the ground is flat and free of obstruction, vehicles become the much better option, as kbots can only go as fast as their legs can carry them (which gives them excellent mobility in things such as snow and marsh), while vehicles can reach far greater speeds when they happen to be travelling on easy terrain.
I think the system doesn't lend advantage to either type of unit, but rather consolidates previous usage "slots" for each unit, so that you would pick kbots to for off-road duty, but the more heavy-duty vehicles for powerful pushes through flat terrain.
Note that I have attempted to affect kbot speeds as little as possible so as to avoid messing up their walk animations. I'm guessing that 10% either way won't be noticeable, and I only once go greater to 20% (snow), which I doubt will be overly visible either.