Shields had some changes on how they protect from critical
damage. From now on you get the full protection by wielding
at least a large enough shield for your size (weight of the
shield and strength of the wielder do not affect the bonus
anymore).
In practice the smaller races can really get full benefits
without the big overwield penalties from the larger shields,
and giants wielding full shields no longer get half the
benefit compared to the smaller races.
The good news come with a slight downtune, I reintroduced
the cap on how much the shields protect, you can no longer
get the almost-guaranteed smallest-crit previously available
for the small races wielding full shields.