Wouldn't all this depend on your target customers? If your target customer is big business that have fast computers you are okay. If your customers are average joes, then yes I would say you should have a test environment in place that closely represents those customers. Even after all that the question I have is which set of customers brings in the most money for you? Lets say you have a mix of big business that run…
A joe-blow at home on the other hand is either at least at the "corporate" level, or even higher for gaming or media-centering.