I wouldn't rate it as any better than powders, but I have found TwinDos works pretty well and I like the relatively neutral scent it leaves behind. It leaves an extremely mild non-floral scent that's a little like Unilever Persil liquid but much less clingy.
The main thing I'm finding is that in a household that has multiple users of the machine who are very heavy handed with dosing detergent, and in an area that has exceptionally soft water, I have been able to cut our detergent use quite dramatically while getting very good results. Also there's absolutely no mess in the laundry room.
So, overall I'm quite happy with TwinDos and it's working out pretty economical given the price of main-stream TOL detergents here (probably much more expensive than Germany) and its tight control of dosage.
Just looking at
https://shop.supervalu.ie/shopping/household-cleaning-liquid/c-150302170 to compare with German or US prices.
1.4l of Persil Small and Mighty Bio liquid (40 wash) - €14.40 (US$15.74/ £12.22)
2l of Ariel at full price €12.60 (US$ 13.78 / £10.69)
Store brand (actually pretty good) 28 wash . €2.45 ($2.68/ £2.08)
Powders :
https://shop.supervalu.ie/shopping/household-cleaning-powder/c-150302165
40 wash Ariel bio €9.00 ($9.84 / £7.63)
45 wash Persil bio €9.30 ($10.17 / £7.89)
I may just switch back to using either Ariel or Persil and a wash booster when I run out of my huge supply of free TwinDos cartridges though as they are quite pricy if not on special offer.
Although, they're still not that much more expensive than a full price pack of Persil here and the bleach cartridge lasts ages as it doesn't use all that much.