Using the Speedtest app we found the mobile hotspot gave a steady 2.5MB/S connection over HSDPA in central London.
Three claim speeds of up to 3.6MB/S and the speeds the MiFi offered feel perfectly usable, to the extent that you almost forget this is a mobile connection.
Speeds out of city centres might be lower, but Three claim to cover 92.5% of the UK in 3G, and aim to up that to 98% by the end of 2010.
Also worth noting is that the E585 does a good job of finding your location in the iPads Maps apps, pinpointing Tech Radar Towers with ease.
Having said that, the accuracy won't be good enough to use with sat nav applications, so it's not a true replacement for the GPS chip found in the iPad 3G.
A speed of 2.5MB/S is fine for web browsing and we were even able to stream live television with no buffering at all, although watching too much video will see that monthly data cap reached very quickly. During an afternoon we racked up 120MB of data.
Other features include the ability to send and receive texts from within the modems dashboard. Accessible by any web browser on PC, iPod touch or iPad, the dashboard shows data usage and text messages.
The E585 has a MicroSD card slot (although no card is included) and the dashboard lets you browse through the files of any card you have plugged in.
Three claim five hours of battery life when in constant use, and our tests have shown similar results, with two hours of constant browsing, TV watching and app downloading accounting for just less than 50% of the battery.
Three offers a range of price plans for the E585, spanning from month-by-month to one and a half years, as well as pay as you go deals.
Their rolling one-month plan includes 5GB of data for £14.99 per month, with the modem priced at £39.99.
The wireless modem can be had for free on Three's 18 month contract, offering 1GB, 5GB and 15GB allowances for £9.50, £17 and £22 per month respectively.
Pay as you go plans charge £49.99 for the modem then offer 1GB, 3GB or 7GB for £10, £15 or £25 per month. The E585 can be purchased with 3GB of data ready to go for £69.99.
The Three Mi-Fi E585 is a fast, reliable and affordable way to get wireless internet on the move, with a range of tariffs to suit all needs.
The ease of use; it really is a case of pressing the power button and throwing it into your bag. A minute later and the E585 is ready to connect to.
The design is compact and attractive. A device like this doesn't need to look great, but the E585 feels well made and looks better than any USB dongle.
Plus Three's one month contract. is a real plus. Mobile broadband might not be something you want to have every month, and you might not want to sign an 18 month contract.
So to make their deals attractive to everyone, Three has a rolling one month contract which you can dip in and out of as you choose.
To keep an eye on your data use the dashboard is simple and functional. Along with the amount of data you've used, the dashboard also displays your most visited sites and files stored on a MicroSD card.
While not quite as competitive as their iPad 3G deals, Three's Mi-Fi prices are cheaper than the iPad deals offered by Vodafone, Orange and O2; and remember, taking out a Mi-Fi contract negates the need to spend an extra £100 on the 3G hardware.
As we said above, the battery will last about five hours, but that's still less than some 3G netbooks are capable of, and while you can plug the Mi-Fi in via USB, that defeats the point of the device.
The current size is certainly pocketable, but if a bigger form factor meant a few more hours' battery life, we'd certainly be interested.
The biggest package Three offers is 15GB for £22 per month and we'd like to see this limit raised so that Mi-Fi could compete with landline broadband.
Some customers might not want to deal with paying line rental or getting an internet connection installed, so offering a larger package with a 30GB limit would be welcome.
Three has the UK Mi-Fi market covered, and offers a wide range of tariffs to suit all needs, twinned with fast, reliable hardware.
For those who bought a Wi-Fi only iPad, or would like to use their netbook on the go without connecting a bulky USB modem, the E585 from Three is the ideal solution, while the one-month plan will appeal to occasional travellers not wanting lengthy contracts.
We found network speeds to be good, connection to be very easy and the five hours of battery life would cover our daily commute and lunch break with ease.