I looked at the Lidl one yesterday, I didn't like it and was glad I'd bought the Aldi ones. It was meant to be a double (it's the only sort they're doing) but it was more like a slightly wider single, plus it was incredibly bulky even when rolled up and very heavy. By comparison the Aldi ones were v. streamlined when rolled away in their bags.
Possibly it was my local Lidl, which is a bit dodge, but they didn't appear to come in proper bags, they were all stuffed into clear thick plastic bags with no tie-top, which would have been enough to put me off even if I'd liked them otherwise.
I saw loads in our local Aldi at the beginning of the week and bought two. ('loads'=about 20) Haven't road-tested them in anger yet, but DH did consent to lie down on one and made lots of 'mmfff mmm ahhh' noises, which I think means he thought it was comfy.