The main problem with the new Touch Diamond phone from HTC is that it wants to be something it isn't.

In this case what it wants to be is an iPhone. It's coming out at the same time as the new 3G iPhone, but it's lacking in more than one area compared with its illustrious competitor.

It looks good, though. HTC's phone design has been getting better and better over the last few years, and the smartphones it makes for the major networks – Orange's SPVs and O2's XDAs are all made by HTC – are certainly looking nicer than they used to.

In this case you've got a slim device that's easy to slip into a pocket, and as the name suggests it's touch-sensitive. As with the iPhone that means there's no physical keypad – there are just five buttons on the front, for beginning and ending calls and navigating the menus.

This is a 3G phone, so as long as you pair it with a suitable network you'll be able to make and receive video calls and use it for fast internet browsing.

But that's where the problems start. The main problem with the Touch Diamond is that it's very slow indeed. Clearly the Touchflo interface HTC have bolted onto the top of the Windows Mobile operating system is extremely power-hungry, because the phone's lack of speed makes it almost impossible to do anything.

If you've used an iPhone you won't see any of the smooth-flowing menus of that phone, and if you haven't, the Touch Diamond may put you off touchscreen phones for life.

It has some redeeming features – there's a GPS sensor (but no mapping software) and an excellent game, called Teeter, in which you have to drop a ball-bearing into a hole by physically wobbling the phone. The web browser works fairly well, and it threads text messages so that you can see all the messages in a conversation.

But the messaging system suffers from extreme slowness as well – in theory you can swipe a finger across the screen to see the next message but in practice this only worked rarely, and the rest of the time either didn't work or registered as a press, which took us to the current message.

And it suffers from the flaw common to all touch-phones: the screen gets covered in fingerprints and smudges which you then need to clean off to get it looking clean again.

The HTC Touch Diamond costs around £400 without a contract, or you can get it free from Orange if you sign up. But we wouldn't recommend it.