For LR I like 1 lb. It takes getting used to though. 3 lbs. is too much for my taste.
2.5 lbs. is about 1/2-1 lb. more than I even like to deal with.
When I'm shooting I don't use a glove though.
Why light - I don't like to have to pull hard on a trigger to get it to go boom. To me, your tigger finger should only touch the trigger when you want it to fire. At that point, it should take very minimal pressure after contact to break.