mark, this can easily pack 2 Jade Shields instead of 3 Mirrors (6 copies of an indestructible shield will hamper draws). Though it will never draw all 12 SoG's in 8 turns, that's how quickly it affords all of them, so it could use a quanta sink (consider Mitosis+target as well). Meanwhile the jump from 1 to 2 DR is huge.
With no quanta sink, 16 Towers is pretty heavy overkill. 13-14 is just fine for a 40 card stall, which frees up even more room for additional MG's or Miracles. 14 is safer in terms of early draws.