Are they using the intel compiler?
Are they making their binaries more thread-friendly?
Are they using cc flags that exploit the new cache/features/instructions?
Are they running their OS's with at least basic tuning to contain interrupts and kernel activity to particular CPUs?
Are they using new hyperthreading efficiently and consciously or just disabling it?
Are they running with taskset wrappers to decrease context switching on an obviously stochastic workload?
Are they tweaking their networking configuration internally to optimize for their specific packet loads?
Because I've found that the new hardware (Nehalems, for example) will give you a heck of a speed boost if you're doing the above.
It's real easy to have the compatibility features mask performance, really you gotta look at it like a new platform.
Anyway, those comments smell like making excuses to me, they are not even remotely specific enough to be defensible.