Never had one myself but a friend is still with them. His driving performance is graded online (things like braking, acceleration, obeying the limit etc) and is scored on a scale of 1-5. All these figures contribute to is the insurance renewal cost for the year after with Co-Op.
Have a look at iKube, Geekman on here used them for the first year of driving, and whilst they didn't allow driving between 11PM and 5AM, they were quite cheap, and then once the year is up, jump ship over to a different insurer so you can drive at whatever time you like. Also to note, if the insurance won't let you drive at night, that isn't just the policy holder, it applies to the whole car, so if it is being used as a family run-around, nobody will be able to drive it at night. (Edit: Looks like he ninja'd me anyway!)
Through my personal experience, the only way for a young new driver to get a sensible quote that is unrestricted is through an Admiral multi-car policy with parents on it with their car, although that could involve changing your insurance too.