Which subspecies is more common really depends on where you are. If you live next-door to a breeder of C.e.e., then that's going to be the subspecies that is more common in your neighborhood! Where did you get them? There are so few breeders in the US, that if you can identify where you bought them, we can probably tell you which kind they are.
Some would say that C.e. popei is more sought-after because the coloration is more interesting. Among some afficionados, the more white flecks, the more sought-after the specific animal is. For this reason, popei is probably more commonly bred, but both subspecies exist in the US.