I have always used a sponge brush for edging and corners while painting the rooms in my house. I tried this Shur-Line corner brush and have found it to be very easy to use and more effective than sponge brushes.
Even though it is meant for use in the corners of rooms, I used it for all of my edging. It covers very well without leaving streaks in the paint. The face of the brush is a soft feather-like surface, not a sponge. This is great because it does not soak up the paint like a sponge does. I did not have to reapply the paint as often as I did with a sponge.
The only thing I did not like about the brush is that in order to get the corner all the way down to the wall, you have to push harder than normal. I still had to use a small sponge brush to get right up to the ceiling and baseboard. Even so, this brush is great for all of your trimming needs.