One extra card in the opening hand sounds tame, but mulliganing with 6 cards is so liberating. The usual mulligan flow if your deck is with enough redundancy (not really having to hard mulligan for any key card, however hate to get the similarly tasked cards) is :
- You pick your initial role from what you see, this gets more varied if your deck is capable of flexing multiple tasks or play with "phases" of using 1H / 2H assets.
- Set aside cards that is not working out economy wise or has slot/task conflict (e.g. cards you included for redundancy ended up coming together)
- Same amount of cards are added back and hope you get a better synergising cards to what you keep, or more "light" cards that can be readily played from hand (Magnifying Glass (1) with its 0 cost and Fast, "I've had worse…", Perception, etc.) So the failing case at this step is when the new cards you get are still conflicting in task/economy/slot.
Step 1 is improved because you see 6 cards and there are many more possible asset pairings than 5 cards. Step 2 and 3 is improved since while mulliganing those cards are excluded out and guaranteed to turn into something else, the more cards you can exclude out the better you can tailor your opening hand.
My evaluation is that this card worth the XP the more a deck can flex (than getting it for the sole purpose of finding specific thing / hard-mulligan). How many ways your deck can flex, at start of the game you gotta be one thing first and do reasonably well at that before you transition to truly flexing. Mulligan mechanics + 6 cards can really let you choose what you want to be at first clearer.
So if you are planning to play investigators that can access Lv.3 and want to not just vacuum clues, reserve early 3 XP and give this card a try! (e.g. Joe Diamond of course, Daisy Walker with her access, Ursula Downs / Monterey Jack fighting with , Vincent Lee getting opening setup.)