Has anyone tried Thirst for Knowledge in the deck instead of Impulse? I know it's three mana, but with 10(or 13 artifacts, if you play both Chalice and Keg) you'll have an artifact to pitch very often.

The pros:

Thirst will often net you card advantage.
If you want to, you can keep more than one of the cards you drew.
(Drain sink)
(Chalice for two won't hurt as much)

The Cons:

It costs one more mana than Impulse.
It doesn't dig quite as deep as Impulse.

Personally, I think that the pros outweighs the cons, although not by much.
Maybe it's possible to fit in both Impulse and Thirst for Knowledge somehow and play, say, three of each.

Any thoughts on this?

Not only do I think it has potential, but I think that it's one of the best decks in the format right now, if not the best. It doesn't have any really bad matchups, Dragon and Control Slaver aside (Workshop aggro isn't a very good matchup either, but who plays that?).
(Don't tell me that Hulk is a bad matchup, because Stax just destroys that deck)

I know the guy who played this deck (and won) at the Danish T1 Championships.
IIRC he said that he included the Pyrite Spellbombs because he expected alot of Welders in the top 8.
I think that he removed 2 Sphere of Resistance(or maybe 1 SoR and 1 Crucible) for them.

Heh. Sure he can Belch in his upkeep, but that won't do him any good, since he doesn't have any cards left in his library and thus doesn't get to deal any damage =P.

You could always attack into the tog, and when your opponent has pumped his Tog enough to kill your Dryad, you put the damage on the stack and play another spell, thus saving your dryad and getting rid of alot of your opponents cards.

This trick only works once, though, or maybe not at all, if you're playing a smart opponent.