Keys start to get a bit unreliable after about 1-2 years.
The Siemens C45 is my favourite phone so far, unfortunatelly I've lost it, but definitely considering buying one again, even second hand.
Phone does not have many features (compared to newer phones), it simply works, and is very easy to use. It is a mobile phone, not a media player, camera, GPS or anything. My favourite feature that I've never seen at any other brand is the automatic switch off function at a preset time of the day.
I've just got a newer phone with bluetooth, camera, MP3 player, color display, etc., but since these features are hardly ever used I still want my C45 back for its excellent SMS typing.
(BTW: I gave 10 points for "Value for Money", but I have no idea how much you have paid for it. It was definitely worth for me.) Very robust. Dropped many times and never broke.
Most convenient SMS typing I've ever used.
Automatic switch off.