Over the past few weeks I’ve been comparing several smartphones. My journey began mainly because my old PDA, a Sony Ericsson P900, developed a fault with some of the buttons on the keypad. Until this happened, I’d been reasonably happy with it, except that it was not very good for taking notes because it lacked a proper keyboard.

However, I have one niggling complaint about the P900’s alarm clock, which doesn’t sound an alarm if the phone is switched to vibrate rather than ring – its so-called silent mode. This seems bizarre. I would prefer the phone to sound an alarm regardless of whether I also want to hear the phone ring. For example, when I travel to the US, I usually put my phone into silent mode when I go to sleep so I don’t get woken by people in Europe who don’t know they are calling me in the middle of my night. I also want the phone to wake me so I don’t need to battle with my hotel’s alarm clock.

A friend had lent me his one-year-old Nokia Communicator, which has a big keyboard, but no backlight. I found it too big and heavy to carry, and its wireless networking and email software too awkward to use. In particular, the email client asks for confirmation to accept the home-grown SSL certificates used by my email provider each time the phone connects to the server, which effectively prevents the phone checking email automatically.

I also borrowed a Sony Ericsson K750i, which is not a fully fledged smartphone. Instead, it’s small and light, and an excellent example of a feature-rich mobile handset, complete with diary and address book. While it’s a great phone and is one of the best phone-cameras, the address book holds only 500 entries. As my Contacts database has more than 1,000 entries the K750i falls at the first fence. It’s also not designed for taking notes, and its diary is not up to par. However, the alarm clock sounds when the phone is in silent mode and will switch the phone on and sound an alarm even if the phone is switched off.

As luck would have it, I had what could be the best example of a Windows-based mobile close at hand – an HTC Wizard marketed as an MDA Vario. This is a neat little handset with a large screen that slides sideways to reveal a small but effective keyboard, so it’s great for taking notes and has an automatic keyboard backlight.

All of which would leave me thinking the MDA Vario is the best bet. Unfortunately its Windows Mobile software is too flaky for me to recommend. Today, for example, I had to reboot it twice to make it retrieve my email. On another occasion its alarm clock was over two hours late. On the plus side, its address book and calendar work well with Microsoft Outlook.

Such ups and downs mean that there’s still no single device that fits the requirements of most users. Perhaps the next Sony Ericsson PDA, due later this year, will be the best compromise in a while.