I really like the fact that the final set bonus for the rare sets introduces a new mechanic but there's a problem. The set stats are garbage compared to just using unique elite gear.

Finding a full set of a rare sets is a huge accomplishment and wearing a full set should be comparable to at least the better elites if not best in slot. This could be done by just changing / adding to set bonuses rather than reworking the individual items. We have enough experience in this community now to define the key stats for each class and these sets should, at the very least, provide an abundance of these stats similar to the better uniques.

It seems to me this was part of the original design, but they just fall short.

Which set is disappointing?

Ok I changed the post title until I can explore more. I used to have 5/6 for baron's set but now I appear to only have 3 (dagger, gloves, bracer). Between the set and my current gear here are the differences

Set: +22 attack haste, +32 cha, +5 stun reduction, +30 fear reduction, +5 life leech
Uniques: +10 mana regen, +25 cast haste

I'll take the mana regen and cast haste all day personally unless I desperately needed the status reductions. Bard melee dps is potato making attack haste and life leech pretty useless in endgame. The five item set will help with the cast haste but the lack of mana regen in the set bonuses seems to be the downfall of the Baron set.

If the intent is to make these rares sets best in slot, which might be the case, they seem to fall a bit short.

Side note, can we get a more advanced item filter by chance? Some of these set items are exceptional quality and it would be nice to be able to filter to only accept exceptional set items and elite uniques.

All of the set bonuses are garbage.. I have a lot of the elite set pieces and don't even try to get bonuses because the loss in stats from using good elite uniques/set pieces is too great.

At that level for example, the 50 AP or 7 life leech or 9 mana/tick is peanuts compared to what would be lost.