The Sense circuit is pretty simple.
I have seen CB wattmeters that are HUGE!
True, they are for 27.185 MHz, and they might not be spot-on, but everyone I ever saw has calibration adjusts.
And by HUGE, I mean HUGE!
The frequency counter matching display has 6" numbers in the LED display.
The On the Air display has TWO! 1165 light bulbs.
Yes, if completely configured, this thing is the size of some rigs!http://www.copperelectronics.com/cart/
And, if you do set to optional frequency counter up to display watts, you can see it from across the room with ease!