We demonstrate scaled InGaAs-on-insulator FinFETs and planar MOSFETs on Si substrate for low power logic and RF applications. This Si-CMOS compatible technology implements SiNx source-drain spacers and doped extensions for reduced overlap capacitances. FinFETs with performance for logic applications matching state-of-the-art are demonstrated. Simultaneously, ft and fmax of 400 and 100 GHz are achieved respectively, the highest reported ft for a III-V MOSFET on Si. Finally, we explore the use of an extended gate line to reduce gate resistance, offering balanced ft/fmax of 215/300 GHz, the first report of III-V RF devices on Si matching state of the art Si-CMOS.