At last, this could have been the support many of us Fish players have been waiting for. For a long time, our options for Coelacanth involved either StarFish (consisting of the Star Blast version, which is the most consistent version), or Genex Fish (which has stirred some debate over it being the best version or not).
Nimble Sunfish not only helps speed the deck, it also helps you dump any fish you want into the graveyard, namely Coelacanth. Why Coelacanth? It can open the doors to some reverse toolboxing if you are running Symbols of Duty in the Genex variant, or it can open the doors to Phantom of Chaos if you choose to run it (also stirred some debate over it's use, but I won't leave the information out...the use is up to the player).
However, dumping fish into the graveyard can also be beneficial for StarFish variants, as it could help feed Pot of Avarice for a second swarm, or prepare that first swarm if the setup was previously prevented.
Sunfish also allows for consistent deck thinning, and combined with Treeborn Frog and Fishborg Blaster, Coelacanth can have enough tributes to be summoned without having to spend any lifepoints, which is quite the plus for StarFish decks.
And last, but not least...Sunfish gives all fish decks the long awaited consistent way of summoning synchro monsters of levels other than those in the 7-9 range. Since Sunfish is level 2, Royal Swamp Eel can help you achieve that much needed level 6 synchro into a Goyo or Brionac.
To conclude, Nimble Sunfish is just what fish decks needed. It speeds up the deck in more ways than one, and facilitates the summoning of our ace card. Once TSHD is released, I will definitely be running to get myself a playset of these and bring back my Fish deck.