The Mobil would need to be 20% or more expensive for me to choose SuperTech over Mobil 1 Personally.
Nothing against SuperTech, I just prefer Vertically Integrated XOM as they are able to provide insanely good performance for value due to their market position and economy of scale.
Case in point, The Mobil 1 ESP line is a phenomenal primarily PAO/Ester base oil with an awesome additive package for $25-28 per 5qt at Walmart.