These are standard Dunlop guitar picks, so we all know what to expect.
They're not amazing but definitley not bad. Like I said just your average guitar pick.
I don't hear a difference between these Flex picks and the standard tortex picks. I think that's just some marketing blabla. But they do feel a bit less stiff than regular tortex. But it's not that noticeable.
They wear pretty fast, but not faster than any other pick.
I play heavy metal with .11 - .48 strings and I pick quite heavily, i'm what they call a "heavy hitter" And these picks last about 10-12 hours of heavy playing before you can throw them out.
In conclusion: Average guitar picks. not bad nor excellent. and exactly what you can expect from Dunlop. No suprises there.