How strongly is the recent "laptop ban" enforced on flights to the UK?

I don't have first-hand knowledge, but reports I've seen in social media posts indicate that there is a separate security screening, either X-ray or hand searches of cabin bags (depending on specific airports, airlines, and gates). To quote the linked FlyerTalk post:

At the IST departure gate there were three checks: the first to manually check your BP against your passport, the second to screen your passport (only one person with a single terminal doing this, so the queue moved exceeding slow), and finally a brush down body search/thorough search of your hand baggage/request to give up electronics. Moble phones were waved through. My iPad and Kindle were put into separate bubble-wrap bags, details written on a list, which I signed, then onto two-part numbered baggage tags, the small tags being given to me. I was told I would need them to reclaim the items. My items were then sealed and placed in a hard-sided suitcase.

At LGW, immediately as we disembarked, those who had handed in electronics were asked to wait to one side. As soon as everyone was off the 'plane, the suitcases were bought out and three members of staff quickly distributed our items to us, checking carefully against the receipt tags. This all took less than ten minutes, although there were only about 15 of us waiting - most people seem to have put their electronics in their hold baggage.