Postcount is as much a standard part of forum posting as it is a bane for many admins and users alike.
Its important as a gauge of activity, but its imperfect, and often times leads to those with lesser postcounts feeling like they are less important to the site.
Have Xen total all of the various things people do on the site into one simple count... Activity.
Remove "posts" from being the main thing to count and replace it with Activity.
Sure, within your profile page somewhere have a count for posts, threads, likes, profile comments, conversations, etc... but have the displayed focus be on Activity and not any one Postcount.
Activity then becomes the main marker with which to gauge who contributes the most to your forum in most possible ways.
You do away with the controversy or confusion of what constitutes a post, you give admins a better understanding of who contributes a lot to the site, allows members to do what they like to do and not feel like their contributions dont matter as much as those of others, etc...
On vB there have been a few ungainly plugins that allow you to do something like this.
Usually they are too involved and too much of a separate entity for people to enjoy them much.
But if its part of the core, and if it sort of replaces the way we normally experience something like "postcount"... i think it goes with the spirit of Xen, which is to take the forum experience to its next evolutionary step.
Breaking away with something as standard as postcount is doing exactly that imo.