We visited one in Polkville, North Carolina while visiting grandma on our big road trip west. Picked up all kinds of stuff at 33-80% off. Tortilla shells approaching sell by ($1 for what would be about $5 at a regular grocery; still chowing down on them 2.5 weeks into the trip!). 25 small boxes of granola bars for $0.29 per box (several months past sell by but we tasted them and decided to get many more - no off taste at all and they've been handy on our trip). Some random salad dressing and salsa that was almost at sell by date. 15 cent big bars of soap (Walgreen's "compare to" Irish spring - not as good as name brand but we get clean and don't stink). Too much candy.
My conclusion was that some things were really good deals, but some things weren't deals at all (compared to Aldi regular prices). The items that were good deals generally weren't very healthy items. This place in Polkville had no fresh fruits or vegs, cheeses, yogurt, milk, etc so not much in the way of healthy living if you shop there a lot.