Now that you mention the plus three sword, it makes me wonder how the "to hit" bonus compares. Does the EB get a bonus to hit to offset not having a magical weapon bonus?
Warlocks can get a Rod of the Pactkeeper which gives a +1/+2/+3 bonus to their warlock spell attack rolls as well as the same bonus to their save DCs. No bonus to damage rolls though. If they take a 1 level dip in cleric or paladin, they can also get the Amulet of the Devout which has a similar effect although I think it applies to all spells the PC can cast rather than just cleric or paladin spells.IIRC they can also stack for a +6 since they're two different items and so are techincally two different bonuses. There's also the staff of power which grants a +2 to spell attack rolls that also stacks.
