Less mana, ideally, and you lose the ability to loop the artifact, but in decks with high-power creatures, youre talking controlling a player for as little as 3 mana
you are right that his minus loses a little due ti all the ETB effects in cube but brainstorm still often just says draw 3 w a shuffle effect and any game where he survives 2+ turns is basically GG
With Trainer cards like Electropower, Electromagnetic Radar, and the Thunder Mountain Stadium to back it up, Pikachu and Zekrom GX came out with a ton of support and little to stand in its way
Charix, the Raging Isle Charix, the Raging Isle is a viable toughness-matters commander that just happens to be a sea creature
Secondly, you can use it to cycle artifacts in and out of the yard those with death or enter triggers, and those that affect all players on upkeeps