After maybe four months of owning the phone, it kept displaying an error message saying 'Invalid or missing SIM', and you'd have to take out the battery and SIM, then re-insert them. This happened for a couple of months, until I realised that the SIM 'clicks' into place and doesn't just sit there. Oops!
One of the styli broke after about seven months; however, the phone comes with a spare so this was okay, and it's less than $A5 on eBay for a new one including postage.
Recently the blue LED on top of the phone has started flashing, which normally indicates that Bluetooth is turned on, or the GPS is connected to a satellite. Resetting the phone does nothing. I'm not sure what the problem is, but battery life has decreased considerably to approximately two days (when new it lasted for up to a week).
All my previous phones had just been cheapies, but I decided to get this one just because it was cheaper than buying a new phone and a car GPS system at the same time. It is noticeably better quality than my previous ones (I've lost count of the number of times I've dropped it on the concrete in the garage or on the slate floor inside... It just comes apart but doesn't actually break!)
This phone came with the standard MioMap software which takes quite a long time to get into. It also came with TomTom Navigator for free, which loads instantly, and I found to be much simpler to use. If possible, get this software.
The GPS sometimes takes up to a minute to connect to the satellite; however, I have found this problem when using other car navigation systems as well as a standard GPS with no navigation. Sometimes it connects straight away after exiting the program and restarting it. The phone comes with the cradle and a car charger, which is good - you don't need to purchase anything else, everything is in the box that you'll need when using the phone.
The phone uses a stylus for nearly all input (there are no number buttons) so typing an SMS is fiddly - you either have to use the transcriber or the tiny on-screen keyboard. There is also something called 'eKeyboard' which puts the normal phone buttons on the screen; this is very slow as well, though.
The rest of the system is pretty easy to use. It comes with Windows Mobile 5 so there are the normal programs like on a PC plus a few Office apps. The phone comes with a USB cable to charge/sync to a PC, and you can easily transfer files between computer and phone.
I have a 2gb SD card and use it as an MP3 player. If you do this, you either need to use the dodgy single-earpiece hands-free thing that comes with the phone, or a 2·5mm-3·5mm adapter which sticks out the side of the phone and makes it a bit more bulky. You can use MP3s as ringtones, and the inbuilt speaker isn't great, but is much better than most phones. It also tries to enable the voice dialing system when in Windows Media Player if the headphones are plugged in, which can be kind of annoying.
The camera is pretty low-quality, with blurry images unless the light is just right and you have a really steady hand! It is 1·3 megapixels, though, so you can take it at the largest size and then make is smaller on the computer and it looks OK on-screen.
The screen is nice and sharp, but any sunlight makes it almost impossible to read. Three screen-protectors are included, but they seem to war out quite quickly. They are very cheap on eBay though.
The phone is able to download emails, but I don't use this feature or know anything about it really. There isn't WiFi inbuilt, so I presume it costs money from the network provider, or you do it via the computer through USB. It does have Bluetooth, but I found it to be a bit temperamental - sometimes it won't hook up to my laptop or other devices, and sometimes it freezes when transferring files.
Overall, I would say that as long as you can figure out some of the quirks, it is generally a good phone, with great build quality. Maybe if you are used to using a PDA you would find it a bit easier. There has recently been the Mio A702 released which has number buttons, a 3·2 megapixel camera, and WiFi inbuilt, which I would definitely look at as my next phone, as it seems to address the things that I found were problems with this one. So while I would hesitate to recommend this phone to someone who doesn't know a lot about computers, I would have no problems recommending the brand.
Previously I stated that the Bluetooth/GPS light was on all the time, draining battery life. I found that after connecting this phone to the laptop via Bluetooth, it now says that the Bluetooth mode is set to 'Discoverable' rather than 'Off'. So I assume it was just something wrong with the OS incorrectly displaying the mode as being in 'Off' when it was actually 'Discoverable'. So, if this problem happens to you, just try connecting it to another device and hopefully the status will be displayed correctly. Battery life is now back to normal, as well.