The "benefits" of any service pack are that it fixes bugs and glitches.
It's not like a new product in that there are benefits to acquiring it and a
ROI decision to consider - a service pack like SP1 is something you should
acquire so that the product you already own more fully performs as
advertised. Since the service packs for Project have all been essentially
free I can't imagine any business case analysis being required before
acquiring and installing them beyond the Knowledgebase article Alexander
referenced for you, and that's the only description of the various things
addressed in SP1 that I've seen in print.
