BenQ isn't a power player in the European mobile phone market and its new E72 handset (announced at Computex) isn't a mass market smartphone.

Exclusively available as part of BT's Fusion package, the E72 acts a GSM/GPRS mobile phone when you're out and about. And, thanks to an integrated Wi-Fi module, it can seamlessly switch over to use VOIP when you're in range of your BT Home Hub router or a BT Openzone Wi-Fi hotspot. Even if you're in mid-call.

You can already see this sort of intelligent network switching on laptops that include 3G data cards or on Apple's iPhone. Devices will automatically use the fastest wireless connection available – first Wi-Fi, then 3G/HSDPA data, and then slower EDGE/GPRS services.

It's as good as the E72 gets

Unfortunately, praising the BenQ E72's ability to hop between GSM and wireless networks is as good as this review is going to get. Yes, so the black and red E72 might be attractively slim (it's only 13mm thick) and surprisingly light (a mere 90g). But this lozenge-shaped candybar phone is also frustratingly underpowered and seriously lacking in features.

Look at the spec-sheet and the BenQ E72 is actually a fairly basic phone. You might expect 3G. But the E72 only has GPRS (and occasionally EDGE) in its locker. You'd hope for a 5 Megapixel camera. You don't get one – the E72 uses bog-standard 2MP technology. Of the 64MB of quoted RAM onboard, only 24MB is user-accessible. You'll need to invest in a MicroSD card to boost the storage.

Even with a 260MHz OMAP 1030 processor inside, the UI (powered by Microsoft's Windows Mobile 6) is horribly sluggish. Quick launching apps via the top-level carousel (showing recently used applications) is far from quick. Below this, you'll find lethargic one-click shortcuts to the Scheduler, Task list and Programs. The start page is certainly logically organised. But clicking through the menus is as joyous as sprinting through stinging nettles in shorts.

On a slightly brighter note, the BenQ E72 features the Mundu IM client, which manages chat access to the likes of Google Talk, MSN, Yahoo!, AOL, Jabber and ICQ. It also boasts applications including: Quickmark 2D barcode reader software, a calculator, a Bubble Break game, classic Solitaire and a ringtone editor. There's also a frill-free photo viewer, FM radio and Windows Media Player software handles any MPEG-4, WMV, H.264 and 3GP video playback.

The Home Hub and Openzone Wi-Fi access does give you a fast and freebie data connection. But the browsing experience on the E72 is hardly worth the effort. The 2-inch, 240 x 320 pixel screen is too small. Web surfing is fiddly and unsatisfying.

Ruined by Windows Mobile?

The more you use the BenQ E72 the less impressed you become. It feels too small for a fat OS like Windows Mobile and the keyboard is too fiddly and stiff for extended (and accurate) data entry. Admittedly, this is something you might get used to. But why compromise? Why struggle when the newest phones now have compact QWERTY thumb boards or touchscreen interfaces?

BenQ isn't one of the big hitters in the mobile phone market and the E72 won't do anything to change that perception. It's a ho-hum mobile handset, solidly-built, but with nothing slick or eye-catching about it. In fact, the E72 is easily eclipsed by entry-level models offered by Sony Ericsson, Samsung, LG and Nokia.

Finally, the BT Fusion functionality is only available if you subscribe to BT's Total Broadband service. Monthly line rental starts at £35 (with 400 minutes, 100 texts) and drops down to £25 (200 minutes, 100 texts) and £19 (100 minutes, 50 texts). As clever as the GSM/VoIP switching is, you have to wonder whether BT Fusion is still a relevant service. Especially with mobile companies aggressively offering hundreds of free minutes to its customers.

Ultimately, the BenQ E72 is a niche handset that just can't cut it in this post-iPhone world.