Noel,
Like you I have had lots of Nokia 6310i, even more replacement covers!!
According to Nokia the 6230 and now the 6233 are the replacement for the old model.
I have spent a few weeks asking friends and comparing different Nokia models on the web, and the 6233 comes out on top everytime.
Like yourself, I find it difficult to use other brands of mobile phone.
I must say I am happy with the 6233. The keyboard on it is very good for typing texts, the display is very clear with the option to increase the font sizes. Also the speaker facility is very loud and clear.
Once you get used to charging the thing up every day, it is good phone.
Carlsberg