Thieves' Kit is a very deceptive card, and the natural card to compare it to is Lockpicks (1) due to both of them providing the ability to gain clues utilizing your agility as a handslot.

It is true you probably wouldn't run both, but this card has an almost entirely different use case than Lockpicks, and wants to be in a different kind of deck.

See, Lockpicks is an engine card. The 1 clue you gain is nice, it lets you make progress, but Lockpicks really exists as a card that makes your entire deck run smoother, more than being the thing your trying to do. You run it to enable large over success tests, which are a key component of rogue, through cards such as Lucky Cig Case and especially its upgrade. In most rogues, lockpick is granting you the ability to take a test at some odd 7 on an investigation, and while you need to oversucceed by 2 to keep the picks around forever, its also letting you, if you use it on a shroud 1-3 location, letting you tutor from the top 5 or so cards of your deck every turn, which lets you generally play the best card in your deck for your situation almost all of the time. This is why its really great in rogue combo decks that have way better clue gathering methods they can repeat. The clue is a (very good, you wouldn't run it without expecting a clue) side benefit to the ability to cheese out tests you can dunk on.

Thieves' kit doesn't do anything close to that. In most rogues its going to be sitting at a base skill of 4 or 5, and while it can get more than one clue a turn, it is unlikely to work on its own to actually get you 3 clues a turn on a lot of harder locations. So with the kit, your losing out on that strong tutor and now need to dump skills and resources into the test to consistently find clues with it, but if you can afford to do that, your now getting 6 clues off a card that cost you, in theory, -6 resources. That is a LOT of clues from one card, and if you combo it with Pilfer and Intel Report (which you can probably afford with this card) it makes a really attractive card to try to base a rogue cluever around.

Rogue cluevers always existed, rogues are exceptionally good at picking up a LOT of clues even, but this lets you go 'action by action' and take what you need to clear locations or pass acts, rather than trying to set up some absurd burst of clues that may not even make sense in your situation or even your player count because you need to get 2 clues off 3 locations rather than 6 off 1 location.

More critically, it actually changes the test to agility, which matters a lot for how rogues operate, because it enables a lot of powerful rogue skills that you can't use with lockpicks like nimble, upgraded manual dexterity,and "Watch This". As a bonus, these skills often benefit from being used on tests where you can sort of game a low difficulty value, or use them on demand, which is normally hard to do because agility, willpower, and combat tests sorta happen when they happen, but investigations can be done literally wherever (and are often high value to do whenever). It doesn't matter how much you over-succeed by lockpicks, it won't rocket you 3 locations away while giving you 4 resources.

So Thieves' kit is actually more a payoff card that your building an engine that can boost it consistently around, with either passive agility boosts, pay to pump cards, or skills, that also enables you to build more exclusively around agility, with a higher total potential payoff. You can compare your expected skill boost between Picks and Kit (If you have a very wide gap between your agility and intellect, Kit makes a lot more sense even if your trying to over-succeed), and that is an important dimension, but ultimately the differences are much more fundemental and you should generally 'know' which one you want from the get go, rather than just trying to cram the kit into a deck in place of Lockpicks (even at level 0 it may not make any sense for a given deck!).

The TL;DR?: Picks are selfless utility tools that happen to also get you a lot of clues over the game, rapidly accelerating your setup and increasing your overall consistency. Kit is selfish and build around that defines your ultimate plan in the scenario and gives you more raw value if you support it.

I think it compares somewhat well to Lockpicks.

Pros:

• No xp cost
• Doesn't exhaust on use
• Gives your investment back and then some
• Ability to commit icons to investigation tests (which are more common than in Rogues)

Cons:

• No bonus to skill test
• 6 uses only instead of potentially unlimited uses

One thing needs to be said is, if you are banking on Lockpicks to have unlimited uses, then you can mentally add 2 to each skill check difficulty. Then Lockpicks is only better when you have 3 or more (with static boosts added).

Let's also take a look at Flashlight:

• Better than Thieves' Kit if your character's ( - ) score is less than 2.

• Better than Thieves' Kit against less than 2 shroud locations.

• Has half the uses

• Cheaper by a single resource

I wouldn't choose Thieves' Kit if:

• My investigator only needs to assist clue getting occasionally.

• My investigator has less than 4 base

• I will have both and static boosts and I plan to have some over-success thing going on

I think Thieves' Kit will see at least as much play as Lockpicks without dethroning it, which is great.

Just don't bother with its upgrade, 3 xp is so expensive for what it provides (+1 skill value and +1 resource return on success).