While there was no end of strategies finding ways to incorporate Thawing Glaciers into their manabases, most people did not make the leap to Brainstorm for quite a while
It costs 5 mana to play morphed and unmorph, it cant be used with enters-the-battlefield tricks, and so forth
You can get in into play easily, either through reanimation or cards like Springleaf Parade that make your tokens into mana dorks
Well also consider the historical value of cards, cards that are iconic and traditional, or cards that see or saw heavy Constructed play
The Dominaria United Commander Decks includes 1 ready-to-play deck of 100 Magic cards (2 traditional foil legendary cards, 98 nonfoil cards), a 2-card Collector Booster Sample Pack, 1 foil-etched Display Commander (a thick cardstock copy of the commander card with foil etched into the cards border and art), 10 double-sided tokens, 1 deck box (can hold 100 sleeved cards), 1 Life Wheel, 1 strategy insert, and 1 reference card