I have two. One to charge one of the three spare batteries. The other to use all the time. The battery lasts for days. The LCD black/white screen is readable in direct sunlight, like a Casio digital watch. The feel of the buttons means I can operate it without hardly looking at it. I dropped it onto tarmac while cycling. The front and back came off. I snapped the three pieces back together and it still worked. If I do break it, another costs £10. The mobile reception is good so it can make calls when others cannot. When the numbers wore off the keypad, a new keypad made it look much better.
The Nokia boom mic headset HDB-5 is a little masterpiece, it fits neatly on the ear and it can be plugged in by feel alone. Yes, the wire gets tangled sometimes but with no battery to go flat, it is better. For cycling, the mic end in a small piece of black foam trimmed to shape keeps the wind noise out. The stopwatch, alarm clock and calculator are useful. Certain callers I have assigned custom ring tones to, so I know when certain people call without having to look. I hold down a number button to dial certain numbers, for example, I hold button 1 for voicemail and 2 for home.
The only problem with this phone is when the keypad is unlocked, if I start dialling a number straightaway it will 'forget' the first few digits dialled and then I have to try again. There is a delay of about 2 seconds after unlocking the keypad before a number can be dialled manually. If I use the speed dial eg 2 for home then this doesn't happen.
Apart from that, it is in my opinion an almost perfect design. I like the Unix philosophy of small tools, where each does its job very well. I see no reason to ever have any other mobile phone for calls and text messages.