I disagree with a PP who said it's comparable to sale prices at Giant or Safeway. That's true about half the time, but at least half the time, it's cheaper. And I used to shop Giant, almost exclusively sale items, for many years.
And when ALDI (or Lidl) has a sale price on something (not a lot of those deals, more at Lidl) the price is ridiculous. A loss leader. Like, IDK-- Asparagus 69c a pound or something.
I don't shop Costco, but I shop Aldi or Lidl about 3x/month.
As often as 1x a month I shop either Trader Joe's or H Mart, because they have stuff that's very specific to their stores (also, DH and DD are Asian American). And I'll do a full shop at that store, that week, because their prices on eggs or bananas or whatever are just fine, and they have most of the kinds of things I buy every week, as well.
I hit either Giant/Target or Whole Foods probably 1x/month too, but not for a full shop. Giant/Target for those national brands and specific items that all the other stores don't have (like a specific cereal or soda or cake mix or something), and WF for items hyperspecific to them. (For that matter, I occasionally hit the farmers market or an even more specific ethnic grocery for their unique stuff. But I do love to shop.)
Aldi and Lidl are just cheap as heck. Depending on when they've been stocked, I do find that Aldi's produce can be hit or miss, but nothing outrageous or disgusting. More like they could have run out of stock, or maybe the celery is a little limp this week or you can only get green bananas. But not for everything on your list. Lidl seems a little more consistent. However, the selection is not huge at either store. You might not be able to find fennel or leeks or whatever (but you might!)
The quality of the packaged goods is equal to that of Giant/national brands, IMO.
It's less overwhelming in some ways to shop at Aldi or Lidl than Giant or a Costco-type store because they only carry 1-2 of each type of item, since they mostly sell store brands. That also makes them physically smaller (fewer aisles, not necessarily cramped). Although overall I prefer Lidl, I will say Aldi has some things I like that Lidl doesn't, I like their seasonal selections better, they're cheaper for some things AND... I find their checkout procedure less stressful. I have ADHD/anxiety so...
Both have you bag your own groceries, but Aldi throws them all in the last person's cart, and you take the cart over to a side counter to bag everything (maybe you bagged some of it as it was being scanned, but not much, because you were probably still loading the belt half the time). This means it probably takes a little longer to actually get out of the store after you've been rung up, and I guess during busy times it might be hard to find counter space, but it's fine.
With Lidl, they just send the items (kind of violently lol) down the belt, where they very quickly start to accumulate before you (Customer #1) can bag them all-- and I'm pretty quick and strategic! They have two sections at the bottom of the belt where they can send them, so after you've paid and they start scanning the next person's order (Customer #2), they send those groceries into the other, adjacent area. HOWEVER. If you have a large order, it's very likely you will be really racing or won't be done before the NEXT person (Customer #3) needs your bagging area. It's stressful IMO. (And obviously if your order is larger than C#2 and/or C#3's, this is more likely to happen.)
If anyone has any tips or tricks for avoiding this, I'm all ears. It's basically the one thing I don't like about Lidl.