Ongoing discussion of cards I think are underrated in Modern.
My contention: Goblin Dark-Dwellers is a pound-for-pound threat, and is a close cousin to the snap-menace that rules control decks with its tiny 50-dollar fist.
Positives:
-generates cost efficient/only slightly conditional card advantage and tempo
-applicable in multiple decktypes
-resistant to chump blockers
-aggro threat (rule of 3)
-extremely good topdeck
Negatives:
-no flash still makes snap superior
-less potent and tempo-based than gearhulk
-not as aggro potent as other options of similar cost
-vulnerable to grave hate
Generates card advantage/tempo- Conditionally, this card snaps in for a 3 drop threat you get for free, and the only conditions associated are the 5 mana to drop the goblin and an applicable target, which is almost guaranteed considering how good the applicable targets are in magic. 3 or less instant or sorcery= every threat imaginable. Opt, sleight of hand, path to exile, terminate, fatal push, abrupt decay, thoughtseize, the list is nearly endless. All the cards you play anyway are snappable in basically the same way they work with snapcaster, except you pay the mana upfront and have "semi"-limited targets (3 or less). In addition, since it has a "come into play" effect, as logn as it isn't countered you retain both card advantage and gain a tempo. I.E. if they terminate it, you still get the snap effect, netting you a +1.
Lots of decktype options- its just red, and even though it takes 2 reds, that's about the easiest condition to fill in the decks that want to use it. Jeskai control, Mardu control, grixis control, burn, and nearly every other decktype that runs instants and sorceries in decent supply (nearly all).
Un-chumpable- Menace, while not the most effective mechanic in terms of aggro ever, is still pretty potent on a 4/4. Since it takes 2 decent sized chumps (at least a 2 and a 2) to bring this bad boy down, you are nearly guaranteed to generate some type of advantage in a blocking situation. Even if they have a bigger critter, they have to chump it into a second blocker, so you will probably get to take down SOMETHING with an attack. And, if they manage to have 2 critters bigger and badder, at least you have the snap in effect to deal with 1 of them.
Decent Aggro threat- as mentioned above, 4/4 with menace is not too bad in terms of a death-clock. On the other hand, I would play this card without menace just for the snap effect, so the menace is just an added bonus. Plus, since you can snap away a potential threat, the 4/4 ness is even more potent. And, it passes the rule of 3 (burn damage used to snipe creatures).
Topdeck-master- since you should have 5 mana available when you start topdecking, assuming its not due to some discard nonsense, this is one of the best topdeck options as you are nearly guaranteed to have the ability to not only play it but to maximize its snap effect, then either have a clock start running next turn or have a decent blocker to buy you some time. And, most notably, this card is enough to not just balance the boardstate, but tip it in your favor. Goblin hits the field, pulls back a creature hate, takes out the big threat, and sits pretty as a 4/4 with menace that gives opponent 5 turns to respond.
Not as good as snap- no, unfortunately no flash makes this card a cousin rather than a sibling to snap. Ah well, it can't be helped. At least it retains more field presence than snap once it hits the field.
Overshadowed by gearhulk- for 1 more mana, you get a more potent creature, at instant speed, with an easier condition on a snap effect. It's true, gearhulk is better, but it's also blue, making the red goblin at least a consideration in decks that don't run blue but still want snap-goodness. In addition, the barrier between 5 and 6 mana is a big one, as you should be well out of the opening by the time you lay the 6th land, so having a gearhulk in the opening hand is a brick while the 5 drop counterpart is at least a brick with a shorter clock.
Aggro-dominated- the exact same cost you can get a thundermaw hellkite that rocks out haste and a snipe effect. But, the hellkite isn't gunna give you the snap effect and is more vulnerable in terms of card advantage than the goblin, so I still like the goblin better.
Grave-hate hates it- unfortunately the goblin shares the same weakness as a lot of the other powerhouses in modern- goyf, snap, hulk, etc.- so there will be side-hate against it. However, even if they side in an answer to the grave, its still a 4/4 with menace, so its not completely neutered, even by the side hate you know is coming.
Conclusion: Yes, its not perfect, and perhaps its not resting at the tip of tier 1, but the goblin certainly brings something spicy to the table, and as its red it gives decks that don't run blue at least the option to consider it. And, its worth noting, that a single goblin hitting the field and snapping back a removal spell is enough to completely tip the boardstate.