I don't have a problem using any one for liq. foundation. They say stippling is supposed to make you look airbrushed afterward, but I really can't tell. I mean it does allow you to layer your foundation, but use less product overall. So you can get light, but easily build to opaque coverage.
With a foundation brush some ppl get streaks because the brush does disturb any layers beneath it.
For a brush like the 109, I don't stipple, I buff like you would with a kabuki (my fave method) It also allows you to layer on the foundation for light to opaque coverage.
Sponges, I use to blend. But imo, you have to dampen them for them to really work and absorb less of your product.
And sometimes it's fun to put on foundation with your fingers! I think brushes and sponges are a hygienic issue more than anything else...
You mentioned finish... I'm not sure that a brush gives you a particular finish... I think finish is a function of the foundation you use. The brush could manipulate the coverage, but not the finish.
Just my $0.02