I don't know if this have been discussed but the Gem of many Facets (new raid) allows you to equip only one item of certain set bonuses - in other words you could as a low level character have several of Khortons island set bonuses on at the same time getting a early needed boost.
Similarly the Epic version of the trinket provides the possibility to equip several red fen epic items without needing both for the set bonus.
There's a caveat - if you read the item it says something like
Gem of Many Facets - Trinket, Anger's Wrath, Protector's Heart, Nimble Hand, Pathfinders, Devoted Heart, Arcane Mind, Archivist, Troubleshooter
Epic Gem of Many Facets - Trinket, Greater Shaman's Fury, Greater Elder's Knowledge, Greater Vulkoor's Might, Greater Vulkoor's Cunning, Greater Divine Blessing, Greater Siren's Ward, Greater Raven's Eye, Greater Marshwalker, Yellow Augment Slot
http://forums.ddo.com/showthread.php?t=275755
BUT - it's specific to what item it acts as a set bonus. For the low level version it's all necklaces. You cannot just equip one of the necklaces without the other part and get the set bonus - you have to equip the other part in order to get the set bonus (the trinket 'acts' like the necklace for purpose of giving set bonus).
That's all well and fine; all the unique items you can only get once per TR is the necklace anyways - you can redo the quest that provides the other item as many times as you want.
However - that's not true with the Epic version (red fen set bonuses).
for the greater marshwalker it acts like the ring - so you get the set bonus with the boots, not the ring alone. And for Raven's eye it acts as the gloves - you only get the trinket set bonus if you wear the goggles.
To me that's a slight dissapointment. I can understand the low level version; for that it's fairly easy to get most out of it since the set bonus is always a necklace. But dependent on class or race different parts of the epic red fen bonus can be very useful. When I first heard of the trinket I thought it was a great way of getting a better value out of the red fen epic stuff since they don't come with a augment slot. And for most part they kind of clash with other really good items that provide augment slots (not to mention the ToD rings).
It's not to say you cannot get an okay mix out of the different items that provide some value but that means that I have to unequip certain green steel stuff and other named items I've collected making once more the red fen epic stuff somewhat of a hmm-k kind of items compared to other things. And while the trinket is a very nice idea I feel less compelled to give up the bloodstone or other trinkets for it with these limitations on it.
It's a tough call, but to me the trinket and red fen stuff is slowly sliding into the whole interesting but possibly not worth it territory again.
One way of limiting the effect of it could be that the trinket can only provide 4 set bonus at any given time but acts as the closing circuit for any item equiped. it's a grind and a half to get the stuff anyways but it's frustrating that the limitations only apply to a few items that I can actually use. To put it like this; if there was no limitations I might've be able to equip 2-3 for the effect but with restrictions it's 1 or 2 - and that's not worth giving up a trinket slot that could go to any item like the new unlockes stones, the eardweller or the desert stuff I mentioned.
Personally I'd like Epic to feel epic - it suppose to be the best of the best - even better than green steel in many ways, but whenever something new comes out it always reinforces that green steel is about the only thing worth grinding for and a few of the original epic items that came out.