I'd have to say Argentea. I've had both and prefer the personality of the Argentea over the Regani. Regani are very shy or at least the 2 I've had over the years were. Regani also a bit mellower too.
I would say,,,,,,,,, argentea as well, between myself and clgkag we have a total of 12, if you look in the photo section I have posted some pictures of my Argentea.