A word to describe a product that has been iterated over many times?

Let's take a product like the iPhone. It has seen many enhancements and update rounds. From the initial prototype to the current version. What word would there be to describe such a product?

I'm thinking of something like "polished" but without the connotation of something necessarily clean. Just something having seen effort put into it. Any ideas?

Solution 1:

It's a product that has been refined with each iteration. However, refined does sound like it would only apply to high-end products.

From MW

Refined - improved to be more precise or exact

Alternatively, you could say it is a product that has evolved with each new version. Describing the iPhone as an 'evolving product' may fit your purpose. It doesn't suggest it's the end of the line and that it will continue to change and improve.

From MW

Evolving - to change or develop slowly often into a better, more complex, or more advanced state : to develop by a process of evolution

Solution 2:

Well-seasoned or honed are indicative of repeated, positive effort. Reworked implies that it has been worked on more than once, although it may carry connotations of prior failures.

Solution 3:

How about 'improved' or 'matured' which could very well convey the context?