Are these good deals for mobile broadband & laptops?

No, it is a poor deal. That is only a netbook that you could buy outright for perhaps �250 or even less if your shop around. You can then buy the same mobile broadband separately, on a one-month rolling contract for �15/month directly from 3. That works out at over �100 cheaper for the first two years and you are not tied in to a 24 month contract.