Controlled-impedance ones sure so. And few cool parts are available any more in thru-hole, so a PCB is necessary to do any serious prototyping. You can sometimes get away with adapters, like the Bellin things, and a lot of wire, but a PCB saves a lot of time for nontrivial stuff. And, as noted, you can add a lot of other useful gidgets to the layout, saw them off, do fun things with them off to the side.
You don't design PCBs?
It's an _Electronics_Discussion_Group!
Possibly so. It's too complex for me to do the numbers, and I don't own a 3D EM simulator. The experiment is my bottom line for now, and it shows that the inverted resistor has less HF parasitics.
No. I measured the entire net effect, and that's all I need and all I have time for.
John