Copying what someone else has already done makes little sense, the pace of the marketplace being what it is today.

That depends entirely on your "business" model.

If you can significantly beat the original manufacturer as far as pricing goes, it might make sense. The customers are more likely convinced to buy your knockoff product at half the cost than the original manufacturer's "improved" version (try explaining these improvements to some manager-type person and why he should pay twice the price for them).

You may even try to sell exact lookalikes which are manufactured cheaply and are of really awful quality. Product piracy still is a big business. And it happens even in safety-critical areas, like medical devices.

With firmware, once understood, it's not rocket-science to figure out a "better" way that differs enough to discourage any copyright infringement lawsuit.

Hm, have you ever had to deal with a competitor who uses patent continuations to move the claims of his patents closer and close to "your" product, using the information about the differences between his patent and your product that you used to defend yourself in the last lawsuit ? Keep in mind that the effective date of a continuation may be the date of the original patent. ;)