I've been rambling quite a bit in the comments of the other recent review of this card, and I think it's time I actually write up my own review.
This card was printed in Winifred Habbamock's starter deck, alongside a few very strong firearms, a context which makes the other review of this card wrong on all three counts.
1) Having to have a firearm in play is really not a huge burden. You already weren't going to be fighting enemies with your fists given you have 3 (and basic attack actions are also just ... never good anyway, given the game pretty much expects you to always deal at least 2 damage per action). The resource cost is also actually quite cheap for what you get: 2 resources, paid once, for +2 to one test per round forever without occupying a slot. Only using the card on attacks isn't that troublesome, either: in a multiplayer game, there's usually a pretty steady flow of enemies coming out of the encounter deck, and you can't get away with evading and ignoring most of them.
2) Wini has 3 and 5 . 3 is enough to be decent with a gun in hand especially given Wini's focus on skill cards (in case you can't find this card or have to make multiple shots in the same round), but the difference of 2 is a fairly hefty base boost. Then add on top of that the fact that if an enemy has lower evade than fight you can choose both options, so you sometimes get even more. And on top of that, there are a couple of Rogue skills that have agility icons and good effects, and the Rogue tarot card boosts agility... And it's not like that boost is going to waste if you were already going to pass the attack, since the guns FFG clearly wants you to run with Wini and this card give bonuses for over-succeeding. (for instance, turning the Beretta's 7 in Wini's hands to 9 sounds excessive, then you realize you want to be succeeding by 4 if possible, or maybe the enemy just has that high of a fight value...)
3) All of the alternative cards listed simply don't work as well for the job this does. Delilah O'Rourke takes up your ally slot (whereas this is slotless -- basically a dealbreaker when you're trying to make that sort of a direct comparison), costs one more resource, and gives half the boost (admittedly to every test, but then that also includes tests made with Sharpshooter?). Hard Knocks ... sucks. You pay the same 2 resources, and same play action in advance, to get the same +2 boost. Without getting to use the enemy's evade value if it's lower, or those agility skills I mentioned. And to do it again, you have to pay the 2 resources again. The only upside is that you can use it multiple times in the same round, if you can afford to throw away money that frivolously (a hard ask with Wini's card draw rate). Well Connected is a card that I love dearly... for Preston Fairmont or Jenny Barnes. Banking 10 resources for a +2 boost is probably also doable for Wini, but it takes more effort than just playing this card and immediately using it. It is a level 0 card though... maybe look into starting with Well Connected and upgrading into this card later? There is one card that was mentioned in the comments which actually stands a fighting chance against this: High Roller. One fewer XP, same resource and action cost, just as free to repeat if you succeed, and can be used on any skill test. It has its downsides which I think are just barely worth more than the 1 XP and added versatility though: You have to hold on to those 3 resources (not nearly as onerous as Well Connected's requirement, but it can bite you). If you fail the test you use it on, you lose 3 resources. You don't get more than +2 against enemies with low evade values.
In short, while this card is fairly niche (the 3 5 statline that makes this card shine like it does with Wini is pretty rare, though it might be okay for a 2 4 rogue?), it is, in fact, the best there is at what it does. Conveniently, as an investigator starter deck card, you have the cards to run alongside it and make it work included in the same pack.