Actually, when I was first starting, I ran a scant 43 card unupgraded deck with no Eternity, and I only lost by deckout maybe 1 in 25 or so games...hardly worth diluting my deck and hurting my win ratio.
Now, I run a 37-card upgraded deck (PuppyChow +2Towers +1Hourglass). I DO have an Eternity, but I've only had to use it once to keep from decking out, over the course of probably 80+ games with this specific deck. Mostly I use it to return Graviton's Fire Eaters, Hermes' Golems, and Elidnis' Forest Spectres to their hands and reset Growth factors.
Basically, were I trying to play unupgraded these days, I'd run something slimmer like:
16 Quantum Towers
1 Fallen Elf
1 Boneyard
2 Bone Wall
2 Otyguh
2 Empathic Bond
2 Rain of Fire
1 Firefly Queen
3 Electrum Hourglass
1 Anubis
2 Improved Steal
2 Phase Shield
2 Quintessence
Quint Anubis early if he pops up, otherwise Quint an Otyugh for munchings or the FFQ in order to pump out Fireflys with which to draw enemy creature-control spells. Once the creature control stops coming, lay out the other crits and Quint them as the Quints come up. Use the Steals very carefully, as they're your only permanent control. You pretty much only want to use them if doing it will secure your control of the board (i.e. snagging one of FFQ's Eagle's Eyes) or win you the game (Gemini's Phase Shield if you've built up enough damage to kill him.)
