No wires is the main reason why I bought this model. The next is the easy attachment to multiple bikes (via rubber bands) as opposed to cable ties, takes less than a minute to swap it to my other bike. Backlit and backlit time can be turned to constant. After a ride I plug it in to my PC and then am given lots of vital data. You can create a course in the garmin connect software then transfer it to the device. I'm a recreational rider / commuter so the heart rate monitor and cadence sensor weren't relevant. If these are important to you then buy the next model up (500 or newer 25). The only thing it doesn't do is display the clock time constantly on the screen. Apart from that I give it 17 thumbs up.

I purchased this Garmin unit really just to give me basic Speed and Distance measurements. I liked the fact that this is all achieved via GPS rather than have to fit up wheel sensors on the bike. The unit fits neatly to the bike (I mounted it on the headstem) - heaps of mounting options though. Great value for money (I picked it up on a price match from Harvey Norman for $129).
Syncs with Satellites quickly, Unit provides so much more functionality than what I needed, Build quality, Price
Would like time of day display on the screen whilst riding