The only times we enter into an Lidl or an Aldi is for the non-food offers, as for the quality of food; we have found it to be somewhat questionable.
I know the stores are smaller than the average supermarket, hence the small product range, but why bother? You end up having to go to one of the more renowned supermarkets to finish a weekly shop anyway.
The whole experience has been unpleasant at times, the small amount of staff that I've seen in one of these stores are generally miserable, they only have one till/cashier operating; so the queue tends to be a mile long.
Each to their own I guess.