I know you can perform a quick look at your off hand by pressing alt, but is there a easier/quick method to compare both your main hand and off hand weapon to a two handed weapon? (When I try compare them, it only shows it against my main handed weapon -besides doing some math)
Then you dual wield two weapons, and you compare a 2 handed weapon, it automatically compares it to both your main hand and off hand at the same time on the damage gains section.
I equipped a one handed crossbow. compared it to my 2 handed bow for an upgrade of 4197 points of damage. Keeping the same Hand crossbow in my primary I equipped another hand crossbow to my offhand, which increased my damage. Then I compared it to my 2 handed bow again for an increase in if 2940 damage.
It shows the status upgrades versus the main hand but its factoring in both weapons. It also factors in a shields stats if you use one.
EDIT: As of patch 1.0.3, 2 handed weapons are now compared against the weapons in both of your hands.