I've seen some users like the ring out option vs. the mobility app (we could try and steer users that way). The downsides to the feature that I think would be greatly improved are as follows, this is VERY similar to the Mitel/Shoretel Extension Assignment feature, but is just a little more simple of a feature.
1. Allow dialing internally to extensions. I can work around it now with a menu and external number that staff use first to connect and then finish with their cell phone, etc.
2. Allow control of the call, placing it on hold, transferring to other extensions, I guess even the ability to have a bunch of speed dial buttons?