Absolutely. Respect for the competitor and open acknowledgement where it's due. Also, Instapaper is a one man show, and this piece made me have greater respect for him .

The article also links to his earlier post on Readability, which too was a welcome break from what one generally tends to see in the tech. scene.

Adding a link here (again), in case people missed it: http://www.marco.org/2011/11/16/readability