I currently have Home Voice running in my home. I use the Home ISA board for IR and X-10 control. When I come home I announce myself with a security code and the alarm system is disarmed, a few lights come on, and any new voie messages are played back to me. As far as entertainment, phrases such as "let's watch a video" or "let's listen to some blues" will turn on all the required components, dim the lights, start the tape or change to the appropriate channel for DSS music. "Let's play some games" turns on 4 pinball machines, a slot machine and a dartboard in my game room. The major problem with voice-recognition is using open-air microphones. I have experimented with several types and various placements. I have had the best luck using the Crown Sound Grabber II units. I have 3 of these connected to a line mixer, then connected to a compressor-limiter which keeps the levels somewhat constant. When things are quiet, everything works great - recognition is nearly 100%. However, once you get several people talking in the room, or you crank up your system to listen to music or watch a movie, the voice-recognition is pretty useless. Unless you tell the system to stop listening, all sorts of strange things happen - lights turn off and on, channels change, etc. So I use the Pronto in conjunction with the VR.
As far as which product to buy, Home Voice is pretty decent, but I'm going to buy the HAL 2000 system mentioned above, as it appears to offer many additional features such as the ability to act as an intelligent answering machine, retrieve information from the Internet and read it back to you, etc.