(11/24/2014) If you have no cards in your library as the ability resolves, the "Form" will be put into its owner's graveyard as a state-based action
In tournament settings, its all or nothing, you must double-sleeve all your cards or none of your cards
This is why, especially on First Edition Base Set cards, the stamp is almost always in the same place
The answer comes down to nostalgia and market size
We played five matches with Historic Soul Sisters and won all five, which is impressive all by itself, even more so when you consider we played some of the best decks in the Historic format (like Simic Nexus, Esper Control, and Golos Field) and topped them all
If you love the look of a particular slab or appreciate the technological approach, they can be a fantastic choice for cards you plan to keep and display