They're great to work with. Plus, since they're all glued in a standing position to the mat, they don't come loose when you drybrush lighter shades on. I'm still on the lookout for some taller grass mats, in the 10mm range to make convincing fields, I think the ones I used were somewhere around 4mm high, to give you an idea of different heights. IMPO, anything below 4mm that isn't supposed to look freshly cut and maintanied, like a yard or city park, just doesn't look natural.
Now I'm giving myself ideas to make a dio of an overgrown city park/playground, that was long since abandoned after bombings dropped lawn maintenance to the bottom of the city's prioritities...weed covered swing sets and old rusty slides covered in leaves, with a ragged teddy bear or hat left to hint at the absence of children playing...now I'm just getting off topic.
"Scanlon: work your knobby hands on the table in front of you, constructing a make-beleive bomb to blow up a make-beleive world."