Does anyone know if the G-Max flushing system on the Toto UltraMax toilets is that much better than the Power Gravity system on the Ultimates? I just purchased a MS854114 for $350 in the Sedona Biege color form Ferguson Plumbing in Sacramento, CA and was wondering if I should return it and order and pay the extra for MS854114S? This toilet will go in an Apartment over my garage that my daughter and grandson will be living in.