Thanks for pointing out that post. It is very useful.

I checked a few themes from leading theme developers and its seems wp_list_pages() is most often used while wp_page_menu() is not present.

As Justin Tadlock points out about wp_page_menu() in the comments:
"It’s a wrapper for the wp_list_pages() function that adds elements commonly-added to themes such as the containing and the “Home” link."