I have been using the old rectangle Distress Ink Applicator/Blending tool for a while now. In my opinion the felt rectangles are too small. But I make it work by using two of them or cutting my own. If the Velcro underneath sticks out it can scratch your card.
But I recently noticed that many people are now using a round version of this tool. I decided to give it a try and I do not like it. The felt has been replaced with a sponge like pad that grips the paper and leaves big ink marks. I had a very hard time getting the ink to blend and was not happy with the change.
Sometimes I just use a piece of felt and not the tool part at all. The long piece in the photo shows that I would use one color and then move down a little bit when I changed colors. The next thing from Ranger/Tim Holtz will be little felt covers for your fingers; like a sewing thimble only felt. You heard it here first ;)
So, have you tired both? Which do you prefer?