Right now I'm running her with Glorf and Theoden actually. A spirit deck that can handle locations, quest, and still attack for at least 9 has been quite fun. Usually it is difficult to still have decent attack in Spirit.

My only issue with this is willpower is so important that if they put out like 4 more heroes with 4 willpower then it will basically force us to always use them. You already have Eowyn and Cirdan (Galadriel can't quest right out of the gate) so if you have a 2 player game 9 out of 10 times people will just use all of the 4 will heroes. Which is why Eowyn and cheap Eowyn (Glorfindel) are used in almost every quest now. They are just too useful not to use them.

I too, would like to see more 3 willpower spirit heroes. Cirdan will be a wonderful addition to get some variety and time away from Eowyn.

I think Idraen can be good in certain situations but it's mainly because of her attack. With her and Glorfindel you can have a mono spirit deck that's hitting for 6 from the start, and that's crazy.

What bothers me about her is her ability. It rewards you for regularly clearing locations, which is a sign that you're in a good position. I like my hero abilities to provide their benefit when I'm in a bad position and need the help. Same reason I don't really like Faramir (Lore). He's at his strongest only when you're not in any danger.

Well, if you're playing mono-spirit, you'll have no problem clearing locations, but how good your position is depends on your ability to deal with enemies.

I think Idrean was worth it just to give player a 3 attack spirit alternative to Glorfindel. I used her for her much needed attackpower in a Caldara deck (I prefer not to use Glorfindel). My experience with her was that she readies almost every turn because I was playing solo-mono-spirit. So she acted as core-aragorn but for free.Theoden might be better than her in that deck though, but he came out later than I used that deck. If we get more ways to add progress tokens to locations, she'll only get better.

Of course she'll always look bad next to Glorfindel, but I find her to be Imrahil's equal.