Yes the brakes were a real problem, Kevin Bartlett was very vocal about it at the time and in his pit lane interview that can be found on YT at Bathurst he didn't hold back - Kev is a real character. The car itself was on pole twice at Bathurst so it had plenty of grunt, but it would run out of brakes too quickly and lap times would drop off. It also won a few Championship races and after discs were added in 1981 it was very competitive. Bartlett offers a brief insight in the following article:
GALLERY: KEVIN BARLETT TALKS ABOUT HIS CHANNEL NINE CAMARO
It's funny reading about the weight reduction they were able to achieve - Dick Johnson was able to get his Falcon down to a couple of hundred kilograms lighter again than the Camaro as the paperwork the Ford crew submitted for homologation for the XD Falcon was for the ute version, not the sedan - it's only illegal if you get caught!
I'm still really enjoying the Camaro model, it has to be one of CC's best efforts. They are still around at retail price down here so you could still take the plunge, I know it's not cheap but I think it's worth it.