I've been running Business Directory on my site for a couple of months and despite so hiccups with my customizations it has run very well. That all changed when they released an upgrade to the plugin.
When the upgrade was released my existing implementation stopped working.
I've seen plugins break after upgrading WP but a plugin shouldn't stop working because a new version of itself was released.
You are taking a huge risk that if you have a successful install it can be broken right under your nose by the developer.