I tried the touch vs type cover in John Lewis. No competition in my opinion.
Touch cover was better than I expected, but a few typos. But the Type cover was amazing! Felt like a completely normal keyboard. I wasn't expecting much key travel due to the thinness of the keyboard, but there was ample to give a normal typing experience. In my quick test I made no typos. Very impressed.
One note for anyone hoping to test them in John Lewis - have a look in the display case first. I asked if I could have a look at the Type cover, the assistant said they only had the 'different colour' keyboards. I pointed to the display case and said 'That one - the one that says "Type Cover" on the box.'
He looked confused. Clearly he hadn't seen them before or realised there was actually a different type of keyboard.