Haven't semiconductor switches, caught up with reed relays for this
application by now, or do they "still" provide a lower "on" resistance,
etc. ?



Semiconductor switches have issues with intermodulation, etc. and power
consumption. For wideband RF, you're not going to be using cheap 4066
CMOS muxes.. if you need to handle strong signals, that implies decent
diodes with a fair amount of current.

High quality sealed relays are inexpensive, very reliable, etc.