I can't really say that either one is better than the other, the Supertech likely uses a modern PCMO add package while the Rotella T1 is an older lower ash package for Detroit Diesels, in OPE engines changed at a reasonable interval there'll likely be no noticeable difference between either, although one may find quart bottles a more convenient for filling small engines over a gallon jug.
SuperTech quart bottles have a big wide mouth hard to pour without a funnel.
I have a 2 gallon jug of SuperTech 15w40 I bought on sale for $20 I will have to transfer it into smaller containers.