@dashrender This is my immediate thesis, I will be sure to share any pros/cons that come from real world use.
1.) Freeswitch is faster and IMHO better than Asterisk. Just park a call and pick it back up for a real world example.
2.) FusionPBX is multi-tenant, rebrandable, true open source. Can run a simple single server install and be expanded to multiple servers. No licenses or add on modules. True FOSS.
3.) I get mod_sofia instead of pjsip, and I ditch all my yealink ghost transfer and ghost call issues.
4.) Better provisioning and its also free. Using Yealink RPS and FusionPBX provisioning you can drop ship a phone to your customer and it will automatically configure itself out of the box.
You can also have a Yealink customer default their existing phone and Yealink RPS will send it new provisioning info when it reboots. So even a customer switching to you with existing phones could default their phones and be up on their new system with you instantly.
Also FusionPBX has templates for all major brands and models for easy provisioning.
4.) No banner ads for SIP Station, Proprietary phone hardware or links that would otherwise send your customers around you to Sangoma.