I've used it.
It's nice, and it makes doing some things very easy. I like being able to take a relay contact, drop it on a line, and have the line cut into two, each terminating at the termination points, and renumber automatically.
On the other hand, the more features of it you use, the more work you have to do.
If you have lots of different kinds of devices in your panels, then you have to spend extra time creating those devices (wich may only be used for the one project) so that it has the proper attachment points.
If you use the "Panel Layout" feature, then you have to provide the database with the spacial dimensions as well.
If you use the "Pricing" feature, then you have to update the database with the new prices every six months when the new catalog prices come out.
And so on. Then there's the up-front commitment that will go into creating all the things that you'll want to do to customize it to the way you do business. Titleblocks. Common parts (that aren't part of the standard library). Symbols that you've been using for years (and like).
Plus training, learning curve slowdown to productivity.
As I said, the program is nice. But I don't know that the ROI is there to justify it. And ROI is king (if you'll pardon the bilingual pun)