The Trish McEvoy 2B Sheer Blush Brush is a classic. It's small(ish) and round (see comparison to Louise Young LY06 Super Blush Brush), of medium+ density and firmness while the hair itself is quite soft. The size and shape make the Trish McEvoy 2B Sheer blush brush good for directional application, while the tapered cut and the hair give a nice and delicate wash of color and never pick up too much product.
Like most Trish McEvoy brushes, the blush brush was redesigned (they also changed the handles from gold to clear). I used to have an older version that died in a freak accident involving a cat and a hamper (don't ask). You can see a couple of older Trish McEvoy face brushes in this post on the Beauty Look Book. I think I prefer the newer version- it's better shaped and doesn't get the blush all over the face.
I like having brushes of different shapes and sizes. I can't choose between them. What you see here is a bunch of really good-to-excellent brushes. My Chanel #7 is not as soft as one would expect, though, so for this shape the Sue Devitt is superior. But all these brushes are great and have unique features- notice the LMdB flatish top (review coming soon). If you're into contouring, the small round head of the Trish 2B makes it a good option (I prefer even smaller and denser brushes that are more forgiving for my pathetic skills). I just use it for most blushes I own, from nude colors to brights, and if there's a need for extra blending it also does the job beautifully.
Bottom Line: you can't go wrong with this one.
Trish McEvoy 2B Sheer Blush Brush ($48) is available at the counters and from trishmcevoy.com.
All photos are mine.