Personally, I'd go for Ephemerate to blink the Micromancer and use it again for more value
Combine Biotransference with the new legendary creature Trazyn the Infinite, and suddenly Trazyn gains every activated ability on your creatures as well as your artifacts
Example: Your opponent mulligans on the play, scries to top, and plays a tapped Temple Garden
If you have a creature with two +1/+1 counters on it and you double the number of counters with Vorel of the Hull Clade, you basically put two +1/+1 counters on the creature, which matters for cards like Simic Ascendancy
Next week, Im looking to revisit a deck that has been collecting dust on the shelf for far too long, Gerrard, Weatherlight Hero
The other reason is much more political: people see the Reserved List as a way rich traders maintain power over the community