Just to update from my last post (#204 on the previous page)
I kept them on my bass for another day and then broke down and bought a new set of spriocore mittels. For me the perpetuals were just a little bit too low tension, mostly for arco because that was kind of pleasant for pizz. That being said I think they bowed fine, maybe a little darker than sprios as others have said but I couldn't get over the "soft" feeling of them under the bow, which is just a personal preference.
After putting a new set of spirocores on I feel like I am back at home. Spriocore mittels are more punchy and louder on my bass no doubt, a bit brighter with more clarity (especially under the bow). I am mostly sharing this to say if you are happy with spirocores you'll probably still be happy with spriocores. Maybe if you play downtuned spriocore solos and you are wishing they sounded a bit fuller then I would say check out the perpetuals, but if you enjoy the feeling of spriocores then I think as it has been said a thousand times before on this site, just stick to spriocores.