Some of the Crye pants/shirts have a version where they are made with DriFire material. From DriFire's site, they seem to make the material out to be more durable, more breathable, moisture wicking and obviously FR.

Oddly, when I see people with Crye clothing, almost all of them have the regular, non DriFire versions.

Is it because the DriFire is usually more expensive and most people don't need/want the FR feature, or is there a downside to the fabric like its actually hotter, or more abrasive on the skin, etc?

It wears and fades quicker.

It is a bit scratchy... But way less than older aramids.

My feeling of the classic US Nomex flight suits were they were hot on summer, cold in winter. Other words, the worst of both worlds.