It definitely gives partial set bonuses. See my screenshot below, which shows one piece of the "Perfidious" set. You'll notice that

• The area circled in green shows what types of pieces exist in the set (helm, torso, pants, gloves, boots).
• The area circled in orange lists the bonuses you'll get as you add more pieces of the set (so 2 pieces gives you +2 finesse, 3 pieces gives you +1 mana regen/sec, etc)
• The area circled red is completely ignorable, as I stole this screenshot from one of my other answers that already had it circled. I'll grab a new image when I can.

As for whether or not there are hidden "complete" set bonuses, I'm not 100% sure, but I believe there are not. As you can see in my screenshot, there are 5 items in the set, but it only lists bonuses for up to 4 pieces. I haven't completed a set so I don't know for sure, but some internet digging hasn't listed any hidden bonuses. I hope to check with the free DLC set soon.

It gives set bonuses based on how many pieces you have, and doesn't always require completion to get the best set bonus possible. See my screenshot below, which shows one piece of the "Captain's" set.

• The area circled in green shows what types of pieces exist in the set (helm, torso, pants, gloves, boots).
• The area circled in orange lists the bonuses you'll get as you add more pieces of the set (so 2 pieces gives you +20% health, 3 pieces adds +20% mana, etc)

There do not appear to be any hidden "complete" set bonuses. So notice that while this set has 5 pieces, the set bonuses only go up to 4 pieces. Adding in a 5th piece has no special effect.

It definitely gives partial set bonuses. See my screenshot below, which shows one piece of the "Perfidious" set. You'll notice that

• The area circled in green shows what types of pieces exist in the set (helm, torso, pants, gloves, boots).
• The area circled in orange lists the bonuses you'll get as you add more pieces of the set (so 2 pieces gives you +2 finesse, 3 pieces gives you +1 mana regen/sec, etc)
• The area circled red is completely ignorable, as I stole this screenshot from one of my other answers that already had it circled. I'll grab a new image when I can.

As for whether or not there are hidden "complete" set bonuses, I'm not sure. As you can see in my screenshot, there are 5 items in the set, but it only lists bonuses for up to 4 pieces. I haven't completed a set so I don't know for sure.

It definitely gives partial set bonuses. See my screenshot below, which shows one piece of the "Perfidious" set. You'll notice that

• The area circled in green shows what types of pieces exist in the set (helm, torso, pants, gloves, boots).
• The area circled in orange lists the bonuses you'll get as you add more pieces of the set (so 2 pieces gives you +2 finesse, 3 pieces gives you +1 mana regen/sec, etc)
• The area circled red is completely ignorable, as I stole this screenshot from one of my other answers that already had it circled. I'll grab a new image when I can.

As for whether or not there are hidden "complete" set bonuses, I'm not 100% sure, but I believe there are not. As you can see in my screenshot, there are 5 items in the set, but it only lists bonuses for up to 4 pieces. I haven't completed a set so I don't know for sure, but some internet digging hasn't listed any hidden bonuses. I hope to check with the free DLC set soon.