I think some are excellent, but almost all of them are overpriced. I also think most are redundant and some are pathetic at best (Athelas at 150pts to have the Hero in question just be Black Darted or Heroic Dueled to death instantly?).
Some seem like they're great, but ultimately aren't: The Galadhrim Bows (or whatever they're called), give you +1 Shoot. At best, that will give you an extra 9 shots, but that's purely if all of the companies can see. Ultimately, it's a waste.
I think the ones in the Battlehosts book are much better, especially the Dwarf ones, but you have to take a Battlehost, which can be inconvenient and, with Dwarfs, often redudant (Why would I pay 75pts for a single Hero to be able to have +1 to Will of Iron rolls, when the Elves get a battlehost where they ALL get it?!?). My girlfriend and I are considering allowing the Battlehost ones to be used if the army is made PURELY from that selection, regardless of Battlehost. It's not overpowered because you then don't have access to Saruman, for example, but it also means that we aren't forced to take a Battlehost that is of no use to us (Thranduil's Halls isn't much use without any forests and, since we're still trying to find somewhere to have a table, let alone terrain, it means we have no forests).
However, I like Steeds of Pureblood (but it should be 35-50pts, definitely NOT 100), Hero of the Hour (drop to 50pts though. Probably not quite worth that much either...), Mithril Coat, The Blessing of Galadriel (about right in terms of points, IMO), Ancient Lore (combined with Floi Stonehand), the concept of Cursed Armour of Udun (although fairly redundant because to affect all attacks against you, it would need to be +2), Evil Reputation (although fairly useless in Evil armies because so many of their Heroes already cause Terror that you may as well take one of them instead), Tormented Steeds (half the cost would be more appropriate), Balefire Arrows (mostly if the unit is large and/or you know your opponent will have more than two or three ents), Tokens of Terror (although you could stick a Ringwraith in for an extra 100pts, but it's cheap and effective!) and a large number of the Battlehosts ones.
Having said that, I would almost always have extra companies over the Fortunes because they cost FAR too much to be considered worthwhile (Going back to Galadhrim Longbows: 50pts for +1 shoot. An extra company of bow armed elves is 50pts and gives you one shot more than the absolute maximum that this can provide, as well as more bodies to soak up damage and more attacks in close combat!), but some of the Fates are worth taking because they are closer to being the correct values (although usually still more expensive than their basic troops, but that's not a problem because of how cheap their troops are).
Anyway, that's my comments, lol. Sorry for the huge block of writing