I downloaded the demo version and it is very interesting. I downloaded it onto my iMac and onto my iPad. Once I figured out the "Push" button meant my updates during rehearsal/show mode would show up for the iPad users, it does seem like a good replacement for a cue light system. However, if you have headsets, I think I would still prefer that, as wifi systems aren't always reliable. (My Martin moving lights have gone out on more than one show....) Though it's not to say that ClearComm or others aren't without their failures as well.
I do think this is more geared towards a conference-style event, as I would expect something Bright or Big to catch my attention when a cue is "called". (A must for a Bump BlackOut Cue.) A small box appears on the lower right corner of the iPad saying "Cue Changed" and my Current Cue is now at the top of my screen with a Standby Cue underneath. All subsequent cues are below a solid green line. I just wish something popped out more and made the current cue more obvious. The reaction on the iPad seems to be almost instantaneous from when I hit the Go button. However, my iMac version just crashed, which caused the entire cue sheet on the iPad to go away and a message says "Lost Connection to Server" and then, when I try to reconnect, I get "No Live Shows." So if there was a back up system of headsets or walkie talkies, there would be no paperwork (unless you remember to hit "Save" on the iPad so that a static version of the cue sheet is available - or printed a hardcopy from the main computer).
With the Demo version limited to 5 cues, and the Lite version (both free) only allowing you to work in Design Mode (which means it won't broadcast cues to any iPad users), your only option for really using this program is to fork over $399 for the Full Version. I suppose you could use the Lite version to generate cue/run sheets. I just don't know if it's worth that much money to me. Of course, if you buy it, does anyone that you need to have cues taken this way have an iPad to receive your cues? Does the company/client you're working for have iPads for show use?