I have been around quite a few of both and I greatly prefer Cardis. I think part of the reason though is they're less common so the ones I know are all sports dogs. More of the pemmies are pets.
To me he pemmies are cattle dog esque and the Cardis are shepherd esque. The Cardis are happy dogs with some drive. Very willing little sports dogs but not super fast. I'm sure some could be but a lot are very heavy. I see more pemmies that are fast comparatively but both breeds are somewhat slowed down as sports dogs ime due to the shorter legs. Not saying you don't see them doing well in sport, you really do but the short legs can be a hindrance depending. pemmies seem a little sharper to me and very vocal.
Mia CGC - (5 year old Papillon)
Summer TG3 TIAD - (10 year old Papillon)
Hank - (approx. 10 month old Spotty Dog)