One uses a varity of soaps and detergents for different purposes;
1) Grated Ivory Soap with a dash of STPP for towels and linens that you want to have that somewhat undefinable softeness and hand feel.
2) Sears Ultra Plus HE powder with 33% STPP for everyday colors (shirts, jeans, et). Works really well on very dirty/oily work clothes.
3) Safeway Ultra Free HE liquid for those days when I don't want to bother with grated soap for the bath towels. It seems to give the softest results of non-soap detergents.
4) Persil powder for use in the Miele for "sanitizing" hot washes (150F to 170F) for tidy whities and kitchen towels.
5) Sears Ultra Plus He with Oxyclean powder, usually as is, sometimes with added STPP, sometimes for sheets or whites or towels or whatever. Works ok in the Neptune up to 130F. A little over sudsy in the Miele at 150F and above.
6) Sears Ultra Plus HE with Color safe bleach and 33% STPP for bed sheets, linens, whites up to 130F.