"It's a shame the brush is raster (pixels are for squares)." This is why I made the comment in my original post.

Sorry, I still don't get what you meant - I assumed it was a dig that it wasn't vector.

If you know how to make a vector brush out of the main vector texture I'd be glad to know.
Not me.

There is actually a Webinar this afternoon from Astute Graphics, so I'll raise the question there and hopefully get some feedback.
OK.

I'm still slightly perplexed as to what exactly I am seeing! The fact that I wonder is a compliment (I think).

It's easier to criticise something sometimes than praise it. I would do you a disservice to say the patch looks great when the issues jump out at me.

If I wanted a patch with lettering on, I'd have created the stitching and overlayed the stitching alone onto a photograph. Your downfall in my mind is that the texture of the denim behind the letters doesn't match the denim of the patch stitching.

Did you make the stitching around the patch?