We investigate the ballistic performance of monolayer indium selenide (InSe) n-type FETs, benchmarking with monolayer WS2, WSe2, and black phosphorus FETs. We utilize first-principles-based quantum transport simulations employing density functional theory and nonequilibrium Green's function. The transfer characteristics, subthreshold swing, and drain-induced barrier lowering of InSe FETs are assessed and compared with those of the benchmarks. Our comparison of InSe FETs to the benchmark transistors reveals that InSe transistors are competitive in ON-state performance, but the short-channel effects in ultrascaled InSe FETs need to be suppressed. InSe FETs are favorable for high-performance applications rather than low power ones.