I love the extension. I had a twm extensions and full shift kit on my Mazdaspeed3 and it was perfect. So I knew I had to figure something for the fist.
Reverse is super easy, lift up and pull towards you. You don't need to have your hand on the knob obviously.
If reverse was away from you, it would be more difficult.
I have the mountune quick shift, it is a must with the extension. I don't like a heavy shift feel, this setup lets me feel everything.
It's not for everyone but I think if you are considering it, you will like it.
I have the Ford carbon fiber knob and it fits good and didn't need to be tapped.
I also have a delrin knob from grimspeed that is perfect, but the top is flat and I prefer the round style of the cobb. The grimspeed knob does look better, it looks more rally style, I may switch back to it.