Less choice, less time spent in the supermarket. I buy 90% of my weekly groceries there and it takes me less than 15 minutes to be out of the door.
The remaining 10%, I buy at different shops as those are really specific items that Aldi does not carry.
I like the low prices and the efficiency of the checkout process.
Anecdote: I have noticed a saving of approximately 15% compared to when I was shopping at the competitor's stores.