Ironically, I think the preconstructed deck is slightly too land-heavy as-is
While some successful lists are gingerly testing one copy, others have put up promising results with an entire playest
The First Sliver and Sisay, Weatherlight Captain are assuredly more powerful cards, but they're fairly interchangable with other five-color legends in their respective archetypes
A sets print run, while not being precisely calculable, naturally ties in with a sets rarity a couple different ways
Collision of the Realms is a relatively light chaos effect compared to something like Warp World, but it could still get a few groans from the table
Sure, the deck has weaknesses: cheap creature removal cards like Go For The Throat, bad opening hands, or simply just not getting enough land