Hi,
I used Comm1 VFR when I was getting my private. It has basic training (phonetic alphabet & phraseology), plus various "scenarios", i.e. entering uncontrolled pattern, transiting controlled airspace, etc. Each scenario has 4 pages - setup/explanation of the scenario, a "virtual" A/FD & sectional for looking up freqs, a radio stack to set up, and then a "Communications" page. When you get to the communications page you listen to the chatter and then make your request, etc.
The way it works is you have several choices for the "correct" communication, written out in text. You make a choice by "keying" the mike over your choice and reading the communication over the headset. Then it tells you whether you made the right choice. If you don't have the radio set up right, etc. it lets you know. If you want to, you can then listen to the recording of what you said and compare it to a recording of a "pro" saying the correct transmission.
Obviously, it is not a true voice interactive program, which is probably beyond today's technology, but I would say it is a worthwhile addition to training. If you look around you can usually find the software plus the headset as a package for a slight discount. It is somewhat limited in that it just has one canned set of "scenarios" - it's not randomized.
I would say from my experience two helpful things for learning the radio are (1) get a really good quality headset so you will have one less variable in your radio equipment, and (2) fly in C and D class airspace as much as you can.
