I can say from first-hand experience that the new Wi-Fi from Three (the one with the monochrome OLED display) is much better than the previous one which had five various coloured LEDs to display what was happening. It's not as pretty when you turn it on as the previous one, but it instead of having to press three buittons to get it working, this new one is a one-button hold for two seconds, and it activates everything in about 45 secs or so. It only has the one button in fact, instead of the three buttons of the former model, which had to be used in sequence.
Quite apart from the much improved display which provides useful imformation, and the fact there is a little green LED on the power button which remains on continually (the previous model gave no indication it was turned on after the five bright LEDs on the front went off after fifteen seconds or so, meaning I often took it out my pocket at the end of the evening not realising it was still on as there was no indication it was) the new MiFi is managed totally via a web browser, so you don't need to install software to manage it, and the SMS facility it comes with can actually be used for sending and receiving messages via the the web browser from something like an iPod touch.
It is a major improvement on the old model, and I'd say that it is now far superior to using a phone for the same purpose, because it is much smaller than any phone, and much simpler to use-- hold the button for two seconds and in less than a minute, your wifi hotspot is fully functional. That's all there is to it, press the button and provided you are in range of a signal, your mobile WiFi router is working.