Here in Walkden, Greater Manchester I hop between Aldi and Tesco and my default is Aldi. It's also entertaining to see that many pricing labels on the shelves in Tesco are marked with an "Aldi Price Match" label. Morrisons too has a Match & More scheme that uses Aldi pricing as a benchmark I believe.
As the saying goes, "Imitation is the sincerest form of flattery".