(1) For bias network design, the main difference is that HBT needs base bias current. While CMOS acts as open at its gate node.
(2) For LNA, HBT has better characteristic to simutaneously power and noise matching, but its linearity is poorer than CMOS while its gm is larger than CMOS.
(3) For Mixer, the flicker noise is smaller in HBT, and the LO swing to full swing the quad of Gilbert Cell is lower than the quad composed of CMOS.
(4) Normally SiGe process is a kind a BiCMOS process, CMOS devices are available, too. The characteristic of HBT is resemble to BJT. SiGe process has many adventage over CMOS, so many company choose SiGe for their RF front-end circuit, then integrate the whole transmitter and baseband using SYSTEM-IN-CHIP(SIP) package.
(5) HBT device is not scalable.