I was going to buy the MY 500 but decided in the end to buy a garmin instead just for the simple fact that you could not use voice alerts.
Think you made the right choice. I have 2 Garmin and 1 Navman, the Navman is not in the same class as the old Streetpilot 3 that sits in the wifes car boot.
If you read through this forum you will see more confirmation of your final choice.
I just bought the new MY 55T. The first unit didn't work at all, didn't even load up the maps, but seemed to get stuck on something called 'mio road assistance' - nothing worked, so i took it back to the dick smiths store and was replaced without any fuss. Well done Dick smiths.
The second unit is great, tried it out over the weekend, and worked really well. The 3d maps and landmark images displayed on the maps is a great addition. The TMC alerts worked for me first time. I think you need to be out driving with a road event approaching before you get that alert. At least that is what seemed to happen with my unit. Every road event you receive remains active for about 10 seconds.
Another great feature is the ability to connect you mobile phone to the device, which allows you to import your contacts, send and receive calls. I really like this feature, and will save you the worry of being fined for using your phone while driving. If you have an iphone, forget about connecting to the device, it doesn't recognise an iphone, but nokia, samsung and other brands will work perfectly.
So whats in the box: the unit, software for windows XP only doesn't work with windows 7 I confirmed this with Navman tech support (and still no MAC support) and I confirmed this with Navman tech support. There's also a wind screen mount, and cable to power the unit while driving, a handy 'quick start up guide will have you using your unit in no time.
I was disappointed that Navman no longer provides an AC/DC adaptor or carry case with the unit, but these are available for about $30 each... I guess the trade off is Navman now offers 3 years of free map upgrades to all new purchases of the MY series but not for trade ins. You need to buy the unit from a participating store to be eligible for the map upgrades to 2010, 2011 and 2012 (Dick Smiths is one of the participating stores). The unit comes with a 2 year warranty, and Dick Smiths offers a further 2 year extended replacement warranty for about $60.
Final words: the MY 55 is a good unit, and definite improvement on my old s90i, faster GPS readings and a clean map interaction with the driver... many new features, including a handy google search.
I hope this was helpful to people considering a new GPS unit for Christmas or just to upgrade.
I downloaded the voice files that were on this site and used the navdsk app and they worked well. Had to boost them up a bit with a wave pad program, but othewise good. You can also record yor own voice, save it as a wav file and use that. Suprises passengers whe your own voice gives a warning.