It's not hard to have more artifacts you're willing to tap to outweigh the one mana to tap it (see: Treasures)
Metal types have gained prominence in recent times, starting with Dialga EX, Skarmory (regular and EX), and Solgaleo EX
Multiversal Passage Saffgor: This not being fetchable is a real downside, and I feel it compared unfavorably to Starting Town
You can easily throw on 5 to 8 counters in a couple of turns in a four-player game, and the more people you add, the faster the Regent will stock up
It was played everywhere, and since it was colorless unlike Akroma, it was played in more decks, and the was the target of Tinkers everywhere
Sometimes you draw a lot in green, and its best to check yourself before you deck-yourself