Sometime around 2010 and thereafter, trade publications and archival journals were inundated with articles and papers filled with hyperbole and lofty claims about the closed cycle sCO2 turbines and their merits. In particular, sCO2 cycle/turbine was/is touted as a technology that can replace Rankine (steam) cycle and steam turbine in conventional fossil fuel-fired power generation, as a stand-alone or as the bottoming cycle of a gas turbine combined cycle. In this chapter, performance of sCO2 in power generation applications (including the Allam cycle) is rigorously assessed with in-depth thermodynamic analysis and cycle data. Furthermore, we will also look at the operability challenges presented by the unique structure of the sCO2 powertrain and heat exchangers.