They need to get more IRIS readers and equipment to read the machine-readable passports and - just as important - they need to keep them operational. Last few times I've been through LHR the IRIS machines have been shut. (They also need to improve signage: lots of time wasted at IRIS machines behind people trying to use them when they're not registered. D'oh!)
Does IRIS still exist?
I came through Gatwick on Sunday and went looking for the IRIS readers and was told "they were withdrawn months ago"