Finally, if you haven't yet, I encourage anyone whose interested in playing MLD, or has played against it, to take a gander at Dana Roach's excellent article a while back, which dug into some of the pros and cons when it comes to MLD
Unlike others, this one isnt bad because its overpriced or understatted, but rather because it benefits your opponents
They were very uncommon in the first 15 years of Magic , and then recently Wizards of the Coast has reintroduced phasing to replace many types of card where flicker was previously used
Many cards can dramatically increase in value when they are graded and encapsulated by companies like PSA or RaukCard
While relative to the field Underworld Breach is one of the slower combo decks in Vintage, it makes up for this in resilence