You could end up stealing something good for seven mana if, for some reason, your opponent plays their bomb into your on-board trick, but most smart opponents will make sure to have a couple of bad creatures around for Riches fodder, which likely makes the average value not much greater than the 3/3 land you get from Rising Miasma
This allows you to shuffle the cards as needed while still offering protection
The Commander's Sphere taps for all of our colors and then can be sacced for a card too, but no tapping
My favorite three decks: Blue-Red 4-drop spells : This is the base archetype for UR, and is supported quite well Grixis Control: As the name suggests, this is basically just all the good Grixis removal and card draw combined, with some lands for good measure
These exist purely for display purposes and require specialized oversized sleeves or frames, since standard toploaders wont fit them