Costar and Cherry are two major stabilizer *designs* in keyboards with MX-compatible switches.
Costar stabs are used on keyboards made by Costar; Cherry stabs are used on keyboards made by, uh, Cherry and some others (KUL, Leopold,…). Most others are similar or clones. For example, iOne keyboards (pre-2013 Razer BlackWidow, the Tesoro board in question,…) have wire stabs similar to Costar, but thinner and flimsier.
Wire stabs are annoying, when removing/installing keycaps and may grind against keycaps/switches, thus I'd avoid them and stick to Cherry. If you don't like the damped/mushy feel of Cherry stabs, those can be clipped to get crisp feel (Ducky does something like this in production). Tape/lube helps with rattle in either design.