This is the updated CZ-999 Scorpion, which is the updated CZ-99. The only difference between this and the Scorpion is the accessory rail. The only difference between the CZ-999 and the CZ-99 is...I'm not sure, except that the factory was destroyed and rebuilt.
Charles Daly/KBI imported them until Remington gave them the screw over their rifles. It has been imported in small numbers in other guises, such as the Israeli Golan (a compact version) and the South African TZ-99, heck even as the CZ-99 direct from Yugoslavia.
Whereas the Springfield XD comes from Croatia, this comes from Serbia and is also the pistol of choice for the Serbian national police and military. Overall, it is bigger than the SIG 226 and fills the hand significantly. They have nice triggers. One might be tempted to compare them with another EAA import (which, coincidentally, occurred only after the previous importer no longer imported it), the Astra A-100. However, the EZ-40 is more Sig than the A-100 was.
Ash