I am still using soapnuts and like them, but do find that I need to use high temperatures for heavy soiled things, which also means they only last that once. For 'non mucky' stuff at 30 or 40 degrees they last for 3 or 4 washes, and do come out soft without fabric conditioner.
I have been websearching today for a petrochemic free carpet cleaner and found some 'all purpose' stuff at
Home Page - Aubrey Organics
Earthaware All-purpose Household Cleanser - Aubrey Organics
now awaiting delivery.
I tried making a soapnut solution but found it clogged my carpet shampoo machine because I couldn't filter it fine enough.