Dimensional Prison, the card that to everyone's joy, has finally been reprinted as a common in the new Machine Structer Deck, has essentially, become a new staple for the format. With the rise of Gladiator Beasts and Flamvells, as well as Blackwings relying heavier on Shura combos, not to mention the fear of Starlight Road(keeping people from randomly playing Heavy Storm), Dimensional Prison has become quite a card.
Attacking has been the essence of yugioh since it first began. Aside from gimmicky decks such as Burn and Mill, you theoretically cannot win without attacking. Dimensional Prison removes from play a monster that attacks. Popular decks currently include Gladiator Beasts and Flamvells. Decks such as these abuse the mechanic of attacking and then special summoning a monster from the deck. However, Dimensional Prison interrupts their attack and removes them from play, thus not only stopping them from continuing with their combo but completely removing them from play. A Gladiator Beast that is removed from play cannot be retrieved with Equeste, just like a removed from play Flamvell monster cannot be revived with Rekindling. This is what makes Dimensional Prison so great. It also gets rid of cards such as Mystic Tomato, XX-Saber Emmersblade and Giant Rat, recruiters as they're commonly known as, they thrive on being destroyed by battle and usually end up killing themselves so that they can special summon a better monster from the deck. Dimensional Prison, in combination with Smashing Ground and Nobleman of Crossout, completely destroy the idea of recruiters. They can't be set, summoned or attack without running into a problem that slows the deck down and puts the opponent in the red.
Also notice that Machines have taken quite a rise in the metagame. Machina Fortress is quite the card, I'll be honest. It can special summon itself from the hand, and even if you destroy it you lose a card and it can simply special summon itself again. However, Dimensional Prison completely stops this tripe. Not only does Dimensional Prison not count as destroying Machina Fortress, but it also removes it from play so it can't special summon itself again, ever.
With the release of Starlight Road, Stardust Dragon has been seeing more and more play. It stops your Icarus Attack, your Smashing Ground, anything that says "destroy" it stops. However, by simply waiting you can use Dimensional Prison to remove from play their Stardust Dragon, which will no longer stop your destruction cards or come back from the graveyard. Which really, is quite important, especially in this meta.
Other very useful cards that are best(for you) to be removed from play include Cyber Dragon, Doomcaliber Knight, Thunder King Rai-Oh, X-Saber Airbellum, Blackwing - Shura the Blue Flame, Neo-Spacian Grand Mole, Spirit Reaper, Machina Fortress, amongst many others. Also, as a quick note, Dimensional Prison is best run in twos or threes, and if you main two you should side the third, it's just that good.