In terms of scratchiness, it's not the softest brush that I have, but it's not scratchy per say. It did smell funky when I first got it, but after washing it a few times (dye does run and it does shed) it was fine. It sheds the odd hair here and there (apparently the MAC one sheds more). It feels quite dense, same density as the Posh. I use this brush to apply mineral powder makeup and for dusting on powder sometimes.
Have you tried the Sigma F45 buffer brush? What is your opinion of it?