After using one at the weekend I've now decided that my life needs to have one in it.
The one I used was a Snap On 18v jobby and was amazing, it costs £470 though.
Now Machine Mart do one for £90ish, it's a 24v one and has about the same torque as the 18V Bosch ones they also sell at £300+ (200nm). Will this be any good? Has anyone used them?