Well now my Rick's fitted with the Stringjoy strings. After doing a bit of playing I found these string to be all what Stringjoy promises them to be. They going in tune directly, didn't need to retune the G string at all and my small test confirmed my intuition, these strings are the perfect set to replace the original Rick strings with the bass downtuned to D.
Straight metal clanking when using the absolute rick settings, while growling dark when using bridge pup and turning down the tone. Sustain is even better then the d'Addario's even though the Stringjoy's are round cores as opposed to the d'Addario's hex which as such are a little stiffer. To me it feels like the tension is more balanced.
So there you have it @RodRy I'm very pleased with these string even though they did cost me a bundle in the end but that's because we have a bunch of thieves at our customs offices, they charged me $25 of which $16 were because of "handling costs" f**king bastards

. Anyway, the strings are worth it and I think they'll last for quite some time.