I have it! And I love it!
But I got at my local CCO, so the price for it was like $43-45, I dont think that I would pay the full price for it. I use it for any kind of all over face powders.
Sorry, but I dont have 123 one, so I cannot compare these two. If you have powder brush already, why dont you get 187 or 182 now (unless you got it too). I think they are great brushes.
I have it, and i hardly ever reach for it. I already have an amazing blush brush (116, 109), I have my powder brush (182), my liquid foundation brush (187). I think you could skip out on it, but i would look at your local cco's before you spend 62 bucks on it.