The BlackBerry Z10 is a 4G handset. At the moment it supports 4G on EE's network, but will be able to run on Vodafone's 4G once its service gets the go-ahead.
With 4G on the BlackBerry Z10 it definitely feels quick. Slapping an EE micro SIM into our phone, we first ran a few searches with the browser. It's certainly quicker than the iPhone 5 we had in our pocket, although we we don't have any concrete stats to quantify that yet, so don't hold us to it.
As for download speeds, the Z10 managed 4.83 mbps with three bars of reception. The iPhone 5 on Three ran at 1.07 mbps with three bars. So the Z10 is quicker, but then you would expect 4G to be.
The exciting bit is that this could end up running on other networks besides EE. Vodafone is calling the BlackBerry Z10 its first "4G ready" phone, which means once Vodafone's 4G set-up turns on, the handset will support it.