Dynamic URLs

Are they still a problem?

[thrasher141]

I remember reading a couple years ago that dynamic URLs (with?= parameters in them) were often not indexed by Google and others.

Is this still a problem today? Is it recommended to have URLs like ".com/products/product23.asp" rather than ".com/products/product.asp?id=23"?

I know that a couple years ago Google wasn't indexing most of the pages on my site as a result of having the dynamic URLs. After I implemented a URL rewriting system, the pages were indexed.

Is it still worth it to rewrite URLs? Any thoughts?