Zello@Work is $5 per unit a month, versus $26 per radio for Passport! I can always tell when Road One is on my scenes, because I hear absolute CONSTANT Zello chirping and beeping!
Yes, you get 5 free users on your account, additional users are $5 each a month. You also get separate servers, and ability to choose bit depth and bitrate, up to 24Khz (bit) at 128bps. :-D