The downsides compared to Looter are a lack of power and an additional mana to get up and running, the latter of which is very significant
Now, Wizards of the Coast can weave in support for different archetypes and open the format up more
Embercleave more expensive or even uncastable
Just a few months ago a major speculator called me crazy for targeting copies of this in Europe for $160, but personally I think its crazy to not be targeting your first copy of this card before nearly anything else on the Reserved List

Azlask, the Swelling Scourge Boneyard Scourge Brazen Scourge Broodcaller Scourge Captain Howler, Sea Scourge Eternal Scourge Gadrak, the Crown-Scourge Goro Rel, Scourge to Spiders Greta, Sweettooth Scourge Gruesome Scourger Haakon, Stromgald Scourge Haakon, Stromgald Scourge Avatar Hinterland Scourge Jeleva, Nephalia's Scourge Judith, the Scourge Diva Kardur, Doomscourge Killmonger, Scourge of Wakanda Namor, Scourge of the Seas Scourge Devil Scourge Servant Scourge Wolf Scourge of Fleets Scourge of Geier Reach Scourge of Kher Ridges Scourge of Nel Toth Scourge of Numai Scourge of Skola Vale Scourge of Valkas Scourge of the Nobilis Scourge of the Skyclaves Scourge of the Throne Scourge of the Undercity Scourgemark Shanid, Sleepers' Scourge Soul Scourge Stingscourger Sunscourge Champion Tovolar, the Midnight Scourge Traxos, Scourge of Kroog Traxos, Scourge of Kroog Warren-Scourge Elf Wildwood Scourge Witch-king, Sky Scourge

The Collector's Edition has a MSRP of US$149.99 , all cards will have Surge Foil treatment, similar to Warhammer 40,000 decks