I've just had my first trip out in the rain with the P&T and the double raincover. I only had one child in the pushchair so the double raincover wasn't really necessary. It took me AGES to figure out how to put it on and attach it, but once I got it on I felt it stayed on a lot better than some raincovers. I still haven't tried to fold it up!
I'm thinking of getting the single one now. Is it a lot less bulky than the double one? Does it attach with press studs to the frame like the double one? Would you recommend it?