I'd disagree with your brother.
I'd say something has got to give.....
Carbon fast taper rods were designed for mono. They transmit every vibration, and can move fish quicker which makes up for the stretch of mono.
Spectra since it has very little stretch has no give when fish lunges or shakes it's head, so not only do you not need a graphite rod but it becomes kind of a problem..
Combine spectra with a carbon fast taper rod and you not only have a rod that has no give but a line that has no give as well and that results in more torque at the hook, which translates into lost fish. Also in my opinion it's just uncomfortable to fish with.
I've played with a lot of rods with spectra and the best ones are more parabolic traditional glass rods because they have enough give to compensate for spectras lack of stretch. I mostly fish with vintage yellow sabres, black glass Calstars and Kencors. As they work great with spectra.
If you want the best of both try a Kencor Zebra.
Magnaglass construction and a spiral of graphite. Since the graphite flexes like a spring they give you more sensitivity but they are still parabolic enough for spectra.
I collect these and they are fantastic for fishing spectra. I'd recommend a Kencor 7ft Zebra Z7X1030, or if that is too pricey a NZKAYK770C which is their cheaper series. I run Diawa 20s on both those rods.
My buddy Byron can hook you up with them. The true Zebra is about $150 the NZ sells for about $60 now that Kencor is out of business.
I think over time your going to see a resurgence back to more parabolic glass or glass graphite rods in response to the spectra fishing market but these things take time.
Jim