Making calls on the HTC Desire Z threw up no particular issues. As mentioned, it's a breeze to navigate your contacts or simply start dialling a number and once on a call the quality is good as well. In fact, the loud speaker on the back puts the Desire HD to shame.
Messaging is obviously helped by the physical keyboard though, as we say, it's not quite the best going when it comes to sheer typing speed. And that's not even accounting for the fact that we can still type quicker with on-screen keyboards. This was at first exacerbated by the fact that the phone defaults to turning word prediction off when using the physical keyboard but once turned on things soon sped up.
Also excellent is the on-screen keyboard that rivals most other high-end touchscreen smartphones. We do find HTC's interface a little cluttered compared to the simpler look of Samsung's on-screen keyboard, for instance, but it's still very good.
Another fine addition HTC has made is the text selection and copying method which has been copied straight from the iPhone. Hold down your finger over some text and a magnifying glass appears zooming into the text beneath your finger and making it easy to place the cursor where you want. Once you let go you can then select some or all of the text and finally cut, copy, or paste it. It really is an incredibly easy way to fine tune your messages.
Text messages are displayed in conversations, so you can follow all the messages you've exchanges with a single contact from one folder, as we'd expect. There are also ample other messaging options available with exchange email, instant messaging (via GoogleTalk), imap and pop email, and text messages all onboard. All told, you shouldn't be left wanting for features in this regard.