Chaos powers are supposed to be used in conjunction with antimatter for more healing, although I get what you're saying. The creature control aspect of chaos seed is quite useful. Generally most decks use around 30, so I packed 37 in just in case they pack in 6 RTs. If they have eternity or PC though....you're pretty much dead.
Actually, is there a chart on deck sizes? I know there were charts on card usage but is there one of deck sizes?