Paul Mc Cann wrote:
snip

For some stuff (fruit and veg) they are dramatically cheaper on many lines.
snip

The ONLY time I ever threw away a complete package of fruit was the time
I got peaches in an Aldi in Dusseldorf. They were utterly inedible, hard
and tasteless.

IMHO the best truism is 'You get what you pay for'

Not always.
The quality is perhaps a bit variable, but there are useful savings
to be made.