The Dragon for email application is simply put, awesome! I have it on numerous devices (BlackBerry and iPad) and it has never failed with dictating my emails so far. Sure, at first it had some issues with my "aboots" and "eh's" but once you learn to get past that it's pretty sweet.
The intial realese of Dragon was not that great for some BlackBerry Tour owners though. Many experienced issues with the application not loading correctly or just simply not working at all. Nuance, the makers of Dragon for email have corrected the issue with their latest release which is currently available via BlackBerry App World. Honestly, I'm not sure as to when it was updated exactly but I am told this will resolve the issue for Sprint Tour owners. Sadly, the app is only available in the US so if you live elsewhere you may have issues finding a direct download for the latest version which is currently sitting at 1.6.2.