I guess our definitions of "worthwhile" differ. I think "worthwhile" is where I don't have to look at my display to get feedback from the unit. I don't need it to sound like someone sitting in my passenger seat.

In my testing I found that most of the things I threw at it were quite understandable, and the few that weren't could be remedied by having a phonetic equivalent stored in another field.

Anyway the thread I linked it looked like there was some thought of "demoing" the Empeg to Alan Black at CMU who writes Flite and its commercial-ware cousin Cepstral. If the guys living in Pittsburgh are still willing to consider that, I'd be happy to help out with any technical details or even help to set up a meeting, etc. I think we'd want to get a ballpark cost figure first though to see if it's even reasonable. I'll see if I can write him this week to discuss such matters.