After many years of abuse, I finally had to concede that my Nokia had reached the end of its functional life. I think I purchased it back in 2004 which would mean it lasted for about seven years.
Its replacement was an iPhone 4s. Since I already have the iPad, I went with the Apple product on the assumption that the interface would already be familiar to me. No problems so far (apart from the children using it as an entertainment device).
The only irritant was changing the service plan from voice only to voice + unlimited data. It took a personal visit to the shop, seven phone calls and two e-mails to achieve this. Each phone call required my personal details to be verified. Four of the seven phone calls involved listening to some really awful hold music. Clearly the phone companies don't have a problem with competition.
As an aside, it is expected that the unlimited data packages will be phased out making mobile internet access more expensive (free wifi coverage is pretty limited in Hong Kong) so I locked myself in for two years which was the longest term they would offer.