When I got FATE through the Kickstarter I was looking for a tool to help describe the "roll" of the dice, and this deck fit the bill with the "Inspirational Phrases" on each card. But what the deck has that make it a really good thing are the "secrets." As I predominately run FATE Accelerated, I found the Quick generation of NPC with the 6 card Arcana deck a real boon as it quickly allows me to build an NPC and flesh them out from that quick deal. The Rule card is also worth the price of admission as I can print that out and give one to each player at a convention game and not worry about it walking off.
DTRPG does a good job at printing these and the material should hold up through a year or so of regular use (I have had other custom decks printed for Savage Worlds and have seen what a year of regular use retains.)
My only challenge with the deck vs. dice is this. With Dice it is entirely possible to roll 4+ or 4- each time you roll. Just pick them up and roll, and then pick them up and roll again. With the deck you have to shuffle each time you want to roll to keep the same probabilities, this can slow down play a bit.
So is the deck worth it...yes if you are GMing, but not so much for a player when you can get the dice.