Experimental results on the performance comparison of two dispersion-managed fibre types in a 500 km (6 x 84.5 km) 16-channel 40 Gbit/s system are reported. The PDF(+D)-NDF(-D)-PDF(+D) configuration showed superior Q performance and nonlinearity tolerance over a broad range of signal power and Raman gain, compared to the PDF(+D)-NDF(-D) arrangement.