The explosiveness is needed, but on turn 1, not on turn 2. Giving your opponents the opportunity to have a turn 1 with no lock component is terrible, which is the main problem with playing a turn 1 metalworker.
No. Just no. A 1st Turn Metalworker is good because it provides ridiculous brokeness on Turn 2. You might not have dropped a lock-piece on your 1st Turn and the opponent therefore could have gone Land, Mox, Mox, Confidant or something similar, but in exchange, Metalworker allows you to blow out fast Trikes and Karn to rip off these resources in exchange which open up a great timing for Spheres again (or vice-versa, to blow out Trikes and Karns under Spheres which protect you from countermagic!).
This is why every MUD should play 4 Metalworkers. I've actually never seen a MUD deck that lost after it successfully got a active Metalworker on Turn 2.
Oath may be an exception, but there you need other lines of play. And it's a bit of a coinflip matchup.
Really? Land, Mox, Mox, Confidant is the go-to broken start for a vintage deck? If a vintage deck goes completely unmolested on the first turn (first and second turn if you're not on the play) bad things happen. Even more than just mana development. There are very few decks in vintage that are incapable of doing something broken quickly and at that point what your metalworker provides may not be enough or may not be fast enough. Beyond that, late game a metalworker can be pretty meh when you either no longer need the mana. I guess that gets a little better if you include Staff for the combo kill, but now you're gutting a pretty significant portion of the deck to facilitate this.
You don't have to choose between playing Metalworker in your list and allways playing a lock piece on turn one....
My point was really more that usually with this deck you can play a metalworker on turn 1 or a lock piece, but not both...unless you have a card that produces 3 free mana to cast your metalworker in addition to your lock piece....
Just for the record, I don't hate metalworker by any stretch. My first incarnation of MUD since the release of Golem had metalworker/staff combo featured, but after playing around with it for a while I found that staff wasn't good enough by itself and I scrapped the combo to fit in more of the lock pieces I wanted for the deck. I still think there is a very valid argument for the inclusion of metalworker in any MUD build, but I was really getting more as to why I didn't think that a metalworker warranted inclusion over a Black Lotus.
