Caerdon Wardrobe is fantastic, though the item indicator only works on unmodified frames, so I can see needed looks on vendors and the AH, but because I use Bagnon, I can't see them at a glance in my bags. The tooltips from it still work there, so it's no less annoying than any other transmog addon I use. I don't mind the icon icons not being in Bagnon so much (there's
a side addon to enable that functionality there apparently, woo!) but it'd be FANTASTIC if it worked in AtlasLoot since I use that a lot to see what difficulty I need to run any given instance on. That may be coming down the pipeline, or may already be implemented (and I just haven't updated to pick it up), or may end up coming from some other addon, possibly AtlasLoot itself.
I'm actually using three addons that do basically the same thing in slightly different ways, because none of them do them all in exactly the way I find most personally useful. CW gives the icons on vendors/the AH/(bags and bank if you're not using an addon for those) but has no indication if you've learned an item of a different armor class except by the lack of tooltip, which makes me nervous because items that aren't part of the appearance collection ALSO give no tooltip indicator, on the default UI or in CW. Example: the Green Holiday Shirt is currently not in the appearance collection (though it was made uncommon quality and BoE like all but one other previously-common/unbinding shirt), and does not have any indication in CW that it isn't in the collection. In fact, the Green Holiday Shirt tooltip and the Green Linen Shirt tooltip (which IS in the appearance collection) are identical with just CW.
Can I Mog It? doesn't actually do much that CW doesn't also do, but I had picked it up before I picked up CW. It adds a line to the tooltip that indicates whether you've learned a particular item, that item's look but not FROM that item, and indicates the same on both items that character can use as well as ones they can't. It adds the "you've learned this particular item on a different armor class" bit that CW doesn't, but doesn't say anything if an item can't be added to the appearance collection.
I was using the pre-7.0 version of
Legion Wardrobe for a long time to keep track of what I needed to make space for and what I could safely vendor/disenchant, both BoE-wise and in the little bit of current/old raiding I was able to do with my bags in the state they were at across my account. It's still absolutely worth using now—it indicates if an item can't be transmogged but, at least on the version I'm using (which does not appear to be the most recent, so this may have changed), doesn't differentiate between items you can't transmog because they're leather and you're mail or because they're not part of the appearance collection. With CW and CIMI? the only bit of tooltip information really needed from LW is "you can't transmog this even if you should be able to," but LW has the additional benefit of adding a lot of extra filters to the appearance collection tab, so you can sort by zone and see at a glance what you have and haven't collected (that you can equip/learn on the character you're currently on) from, for example, Gilneas/the worgen starting area. It also adds a larger preview frame in case you want a closer look at a piece of gear in the collection, or to rotate it or see it on your character proper instead of on a shadowy version, though I don't use that feature that often.
So my tooltips are a little unwieldy and if one or more of the addons completely replaces the bits of functionality I like from the others I'll eventually be able to pare it down, but it's not super bad for now—this is what the different bits look like on my rogue, for example:
Legion Wardrobe is the most likely to get replaced in the tooltip department (since it only does one thing the other two don't), but it also gives you SO MUCH MORE information about locations of things than the default collection does that I probably will hang onto it even without; you can pull up a list of identical looks and where they're from, including zone, quest name, and wowhead links for the quests and/or items in question. Pre-7.0 it would also darken item appearances you already had on the auction house item list, which was super useful (and very similar to CW but in reverse, actually), though I'm not sure if that functionality has been reintroduced in the new version or if it's on the table or what.
Also worth getting, since I've sort of meandered away from CW specifically and transmog addons more generally, are obviously
MogIt, which most people are already familiar with but is great for putting together sets or looking at multiple pieces of gear at once, and
AtlasLoot, which (again) a lot of people already use, but is great for figuring out if you need to actually bother with an optional boss or sit around for three minutes waiting for the Saronite Animus to spawn on Vezax (or figuring out which bug to kill last on bug trio in AQ40, that's been the big one for me lol) or what.
