Centrino-M Question

Friend of mine plans to get herself a notebook. I thought about suggesting a Centrino-M-based system since those are already available at around €750-900. Unfortunately, some of the reviews I read were rather contradicting or unclear. Some said the battery performance was notably worse compared to standard Centrino notebooks, some said it’s only slightly worse.

Anyone have experienced with those? It’ll be mostly used for office work and accessing the internet, so gaming performance isn’t relevant. Battery lifetime, however, is.