You're assuming they don't already have MS Office licenses. I'm pretty sure those 20 employees are using some sort of office software right now. Heck, they may even using DOS versions of Word Perfect, there's no way for us to know. So, you may be suggesting that they scrap software they've already paid for to switch to new software that will almost certainly require at least minimal user retraining, and added costs that aren't necessary.
Performance? Really? Personally I'd want stability, reliability, and top notch support. Your average computer user loses far more productivity from downtime due to cheap hardware dying, unstable drivers, etc than to their machine starting (insert app of your choice)
.2 seconds slower. I want to be able to order an exact replacement 2 years down the road if a machine dies. I want replacement parts available for the forseeable lifetime of the machines on which I standardize.