EAA/Tanfoglio's pistols are used by some of the best competition shooters in the world, including Eric Grauffel, Ben Stoeger, and JJ Racaza. Their Witness series of pistols use the same frame-over-slide design concept as CZs, giving them a low bore axis that helps fight muzzle rise under recoil.
If a gun doesn't meet the USPSA Production requirements, but is not ported and has iron sights, it will most likely meet the USPSA Limited division requirements. The Limited division allows things such as slide lightening, >10 round magazines, no weight restrictions, mag-wells, all sorts of external customizations, and has no restrictions on holsters or mag-pouch positioning. It specifically does not allow Optics of any kind and/or barrel porting or comps. The exact restrictions can be found in Appendix D2 of the USPSA Rule Book.
