OK … I’ll be interested in your opinion … 
Persil powder for me, its the only one Ive not become allergic too over the years
never use softener , white vinegar works better, doesn’t coat the fibres and keeps the machine nicely clean and sweet smelling
I see you found your excitement. 
I use whatever non bio powder is on offer, either Sainsbury’s own or Surf, whatever. I usually use Sainsbury’s own fabric conditioner but I water it down, really don’t need it full strength. I find the fragrance of some powders migraine inducing, especially the all-in-one conditioner ones, (Bold?) really makes me feel quite ill.
I stopped using liquid regularly as it builds up in the machine and makes it smell, even with a fairly frequent machine wash cycle. Our water is very soft, not sure if this has a bearing but I know others in hard water areas have had the same problem with only using liquids. Interesting about the vinegar, Jean, might try that, do you just pour it into the conditioner bit?
I still do use liquid detergent occasionally though especially on dark washable woolies so I don’t get specs of powder.