I replaced a 6120 BlackBerry with this phone. I was astonished at how easy it was to set-up. It comes with the OS already installed (Microsoft Mobile 2003). The VOQ Mail Pro software is really nice and better than Outlook. The boot time is a little slow but that is the OS not the phone (its Microsoft Windows, come on ppl).This phone works great on the Cingular network. I receive an excellent signal. Much better than the Blackberry (on the T-Mobile network). The usability with this phone to navigate back and forth through the features is great. Again, better than the blackberry 6120.I will be buying more of these phones in the future if I can get access to them. Sierra Wireless discontinued this phone which is too bad. I reviewed many many smartphones and PDA's before making my choice with the Voq Pro phone. For the price ($150 US) this phone has met and exceeded in some areas all of my expectations. I considered purchasing the following:- Treo 650- Samsung i730- iPAQ hw6500The only feature I wish this phone had was bluetooth for transferring files between my phone and laptop.