The outlaw synergies have only been introduced recently, but they have a lot of depth since assassins, mercenaries, rogues, warlocks, and pirates have years of support, not to mention how cracked Treasure tokens are
For players intending to stay closer to home, the Classic carrying case and the game board are beautiful display pieces
Ask yourself how the veterans in this hobby, that are still around and continue to do this, got their collections where they are today
This functions like a very strong version of Clone, but I dont expect phones to become a mandatory part of the game any time soon
Mardu is the most popular color pairing, followed by Sultai, Bant, WUBRG, and Simic
Then regarding Spanish cards, they are printed in the US and The Netherlands (so made by Millenium Print Group and Millenium Print Group Europe), so you are right that they are not printed in Belgium by presumably Cartamundi and thus wont have those filler cards