The extra body is not totally irellevant. The EsperDecks in my meta plays Spell Pierce as only counter also, so Stoneforge works around their counters. The card advantage is also not too bad, getting a 1/2 and a Jitte to attach it is nice. Also, when you play sylvan library the shuffle effect from stoneforge is really nice.
Its a love hate relationship this damn Stoneforge, as someone pointed out a couple of pages back I hated the card, now I am back playing it. I guess that the card improves the miracle/stoneblade matchup too much to cut it but I would not go that route against RUG/Goblins since it is too slow.

