This is a really cool article. Everybody in the PSoC3 world must go through this App Note.
This article doesn't reinterate that for best analog use, should prefer P0, P3, and P4 usage that other ap note mentioned.
Is this no longer true ?
The use of P0,P3 and P4 as the preferred port for analog is still valid. This app note gives you an overview of the pin architecture and how to effectively use the various features available with GPIO and out it to best use. PSoC Creator provides an easy way to program the pins. You can make a wise decision as far as the pins is concerned with the help pf this APP Note and the other APP Notes referenced in this App Note.