I go to Aldi for nappies and wipes. Sometimes I will get biscuits.
I find most of their products to be inferior though, especially fresh produce. I have gone to buy bread a few times only to find mould, bleugh. There was once a huge crate of packaged naan bread that they were trying to get rid of near the checkouts, full of mould. The 'fresh' flowers for $5 always look at least one week old, wilted and dying. The fruit and veg...don't get me started. So much rotten produce. I have shopped at Aldi in a few different cities that I have lived in, and they have all been the same.
There are savings to be had, sure. I prefer to spend a bit extra and get a decent product though. Their nappies and wipes are great, however I don't think i'll ever go back once the kids are out of nappies.