I was going to start a topic on SNB too, but you beat me by a minute or so, lol.
So anyway, I'll just copy and paste everything I wrote here......
Sword and Board (as everyone knows) applies a % of your Shield's physical armor as physical damage.
However, the skill is relatively weak because it does not scale off anything else.
+% Physical Armor and Vitality does not improve the bonus damage of Sword & Board.
Strength / Focus does not improve the bonus damage of Sword & Board.
I'm currently unsure of how +% to All Damage interacts with Sword & Board, but I'm going to make a wild guess and say that such affixes function in a similar fashion to STR/FOC damage scaling, and thus do not affect Sword & Board.
I have a few suggestions to fix Sword & Board.
1. Allow Sword & Board to scale with +% Physical Armor and Vitality.
+% Physical Armor is a relatively useless affix, and this would give some use to it. Bulwark and Heal Bot also provide +% Physical Armor, so there is some skill synergy going on there. Vitality is always a useful stat for melee classes, and SNB Engineers are primarily a melee class. This would probably allow Engineers to scale into end game, since there are Enchantments and Sockets for +% Physical Armor.
2. Sword & Board considers total physical armor value instead of just the shield.
SNB would tie in well with Aegis of Fate which uses a similar mechanic, and SNB Engineers have a reason to try to get high physical armor values. (Of course, Aegis of Fate needs to be reasonably buffed first......)
3. Sword & Board considers all armor values (Ice, Poison, Fire, Electric) instead of simply just Physical.
This would outright improve SNB although certain Shields with Elemental Resistances would be favored. Naturally, Fire/Electric Armors would be favored due to Fire & Spark.
4. Sword & Board scales with STR/FOC.
Very self explanatory suggestion. Any skill which doesn't scale well sucks at the end game. This is one of the ways to have SNB scale.
5. Increase the % multiplier for SNB.
Another duh, but I guess it needed to be stated just for convenience/completion's sake. Hopefully, this would be the last option to consider.