A large Lidl opened in the nearest town last Thursday, so I thought I'd go and take a look. Must say that compared to Aldi (just down the road from the new Lidl) it felt very cheap: harsh lighting, amateurish displays, naff signage - with prices written in fake felt-tip pen - and a generally second-rate feel to everything, in spite of it being brand new.
All-in-all, it made Aldi look like Waitrose, and no amount of low prices would make me go back.
Does it really matter?....unless you intend to spend all day there, or apply for a job.
I think differences are quite branch-dependant, but both Aldi and Lidl both have that "continental supermarket" feel.
ginge - I think comparing them to German supermarkets would be more accurate, rather than "Continental" in general. From our experience supermarkets in most European countries are very similar to ours.
ginge - the Germans aren't big on supermarkets - Walmart tried there and failed and the Dutch don't seem too keen either. The Belgians, Swiss, Spanish and French are more like ours and the Tesco in Prague is most impressive. In Austria the EuroSpar are very good.