Sure Doomsday has its problems, but doesn't every card in Magic? The fact that you can lose to EOT Ancestral is actually pretty cool
You really do need to play with Doomsday a lot to see all of the possibilities, past gold fishing. Most of the time I will have an Animate in hand along with either 1 of the three key cards, Dragon, Swarm or Bazaar. So, you can usually afford to stack 2 Animates and use the 1 in hand to run them out of Counters.
I'm not having a difficult game vs Keeper or Mono U right now, neither of them seem to be packing specific hate tho'. Finding a way around Chalice seems to be the imperative, so sneaking in a Necromancy or boarding 4xOxidize (which you should really do anyway) seems mandatory.
I don't think Doomdsday is going to do much in BUG Dragon, losing redundancy destroys the decks Tempo vs Control.
I definately think it belongs in Spoils-Dragon tho', I never liked Necromancy with out Moxen and the ESG->Swarm synergy is too important for the deck.