I was bugged by having to bag my own groceries, put a quarter in the cart (nearly unheard of outside of Aldi where I live) and having to pay cash (they take credit cards now). But a few things happened: about 80% of what I purchased as "store brands" were superior or dead on par with the name brand (a few were misses, a few were dramatically better). The total spend on produce and meat was significantly lower than I typically paid and I noticed when I was purchasing the produce that the quality was very consistent. My green grapes, the kids favorites, were much smaller than I typically bought but it turned out that makes them sweeter and there were fewer brown buggers in the bag.
As to the bagging, I am beginning to prefer it. They always have empty cardboard boxes and a large counter to organize things and because we intentionally grocery shop no more than once per month, I end up with a huge amount of things (we do joke, however, that it's impossible to get a combination of things at Aldi that fills the cart and results in a bill greater than $220 -- my current record highest). Organizing it in boxes according to what fridge/freezer/cupboard it will end up in makes that part of the process a lot easier (easy enough for the kids to do it without our help).
And for the quarters, this tiny little deposit results in the carts being put back in the bay. It saves them money, sure, but it has two other benefits. The bay always has carts -- I don't have to surf the parking lot during the holiday season because all are in use or scattered through the lot. And unlike every other store where more than half of the carts have problems, Aldi's are always in perfect working condition. No stuck or crooked wheel forcing me to push the thing sideways to make it go straight and I'd imagine that has cut down on damage to parked cars, too.