I use one for matches and they really work. The brass doesn't drop quite straight down, but very close to it. More importantly, the brass is in a nice neat group at the end of each stage. No more groping around especially after the offhand stage.
BTW, I picked up one of the low cost ones from John Masen. It's cheaper than the one Bushmaster sells.
There are two downsides:
It puts a little dent in the case mouth. It's no big deal as the expander irons it out.
It marks up the underside of the carry handle where the retainer detent snaps in and out. That may bother some people.
EDITED TO ADD:
I almost forgot one more thing. If you reach through the carry handle to trip the bolt release, the deflector is now in the way. You'll have to reach all the way over handle to trip the release. I suggest at least a dry fire session or two to get used to the new programming.