So, I figure that it's time for a thread to revisit items in general, and discuss how things have changed (or not) since they were last discussed.
Troll Heart
I don't know about you guys, but I'm finding this item so overpriced that I almost never buy it. The troll heart still works for 1st level rogues, but for everyone else it's a pretty steep cost and it's no longer worth a lot of CP when you finally decide to toss it. Either needs improvement (probably CP) or a cost decrease.
Pendant of Mana
I'm really on the fence over this item. It's not bad, but it's pretty mediocre across the board. Below-average effect, below-average CP, cost is unremarkable (neither really high nor really low), large item, and seldom lines up for a good combo. None of those on their own are a big deal, but taken together I'm given to think the item needs something.
Piercing Wand
This item is really niche in its current form. I haven't bought it in months, and it only occurred to me recently that it's an item that I never use. It has piss poor conversion value, it only works on a very narrow range of monsters (and really is only practical against magic-resist bosses), and requires a large expenditure of exploration space to function effectively. Beyond that, its actual effect isn't very noteworthy. The piercing wand needs something; heck, I'd go so far as to say combine it with the battlemage ring and ditch this item completely.
Battlemage Ring
This item's alright, but overpriced at its current cost. I never pick it up unless I'm really dedicated to fireball'ing and already have a strong spellcasting combo running. For everyone else, it's just too pricey for what it does. Maybe if it gave some decent CP...
Platemail
This item, in my books, is just way too good. Until you hit vicious-level damage absurdity, it just lets you tank through pretty much everything in the game without flinching if you combo it effectively. It's completely overshadowing just about every other preparation, and it definitely needs a nerf.
Balanced Dagger
After playing around with this wacky item a bit, I've found it just a bit too impractical. It's not good enough to merit bringing it as a preparation, so you're stuck using it from a shop. Its medium cost and low CP is already a big disincentive to an in-game purchase, but the deal-breaker is that it requires you to fundamentally change your monster-slaying priorities before you find it in a shop. Normal gameplay involves killing higher-level monsters, which means that when you level up there are relatively few monsters that are equal-level to you. It's not uncommon to reach the 5th level and already have killed all the 5th level monsters, which means there's virtually no benefit to picking up this dagger.
I love the way this item fundamentally changes your game-plan, but for a veteran player who knows how to leverage bonus experience (that is, anyone who can actually beat thief silver to unlock this thing...) it's just impractical. Not sure what the answer is, but I'd hate to see something so original and interesting just disappear from the game. Unfortunately as it stands, it'd be my top pick for veto if I were actually inclined to veto items.
Venom Dagger
Still feel the same way about this item. Just too niche as it currently stands, and basically only useful for a glass-cannon character build fighting a glass-cannon monster. For anyone else you probably want to attack more than once in succession which will break the venom dagger's poisonous effect.
Stone Sigil
Good item, but kept down by high cost and low CP. Consider a small tweak in those departments.
Martyr Wraps
The offensive counterpart to platemail's defensive, Martyr Wraps are just dominating currently. The issues essentially are threefold: spellcasters suffer little from the downsides, there is no corrosion cap so the damage you can deal gets obscene (particularly for monks, gorgons, and paladins), and there are a couple of reliable ways to clear large stacks of corrosion and purge yourself of the downsides just before the boss battle. I'd say something needs to be done about all three to bring the wraps into line.
Mage Plate
This item was definitely too good for spellcasters and gnomes, but offered some neat tricks for other character builds. Now it's only good for spellcasters and gnomes. A little middle-ground would be nice. Either soften up its downsides or give it another interesting upside.
Avatar's Symbol
Still a mish-mash of unremarkable abilities that don't seem to combo particularly well with any class. Also has a ludicrous kingdom cost as a preparation, which is not warranted for an item that is at best on par with the fine sword as a preparation.
Namtar's Ward
An interesting novelty; sadly not locker worth aside from a trophy but I can understand why it wouldn't be buffed further. It has the same issue as the Avatar's Symbol with an unrealistic kingdom preparation cost, which should be brought in line with stuff like the crystal ball.
Sensation Stone
With the stacking orc gone, I'm increasingly convinced there's nothing wrong with the old 225 number for this item. Considering there are already items that are directly comparable to a couple hundred CP for each race, I don't see any real issues with improving it up to those levels.