I have previously posted my opinion on this, but will do so again as the
topic seems to have generated interest. I have ound that encumbrance, not
just being encumbered, has a definite effect on dodging and damage taken.
When I am at my low weight, about 30 lbs below encumbered, I dodge about 3-4
times a fight and can solo white creatures. I take only slightly more
damage than my banded wearing ranger friend even though I am clad in
leather/mesh with a Crush's tunic. Although I take more when hit, I dodge
more often. as soon as I approach my weight limit I begin to dodge
significantly less, and take more damage on a hit. Monks experience this to
an even greater degree, but I think it affects all classes somewhat. Hence
I have found that despite wearing lighter armor than most bards of my level,
I do not take significantly more damage because my encumbrance is so much
less. I have also found I run slightly faster at light load than at full.
Haven't timed it enough times to be sure it wasn't the vagrancies of
connection, but it was about a 5% difference in speed crossing Kithicor.

Kitasi in Leather