After 2 visits (one on a busy Sunday late morning, the other on a laid-back Tuesday evening -- last night just before closing) I want to add my agreement that there are definitely more "plusses" than "minuses" with Mariano's. I think the challenge laid out in all of the posts above is how to define what Mariano's really is. It doesn't really fit into the Dominick's/Jewel archetype, the Whole Foods archetype, or the "neighborhood market" archetype, though it shares both positive and negative elements of each. Maybe the challenge of pinning it down is what alternately frustrates and excites a lot of the recent posters? But one thing that should be made perfectly clear is that Mariano's is a
supermarket. If the "supermarket" concept is opposed to what you believe food should be about, you probably won't be swayed into making regular visits there. If supermarket shopping is what you enjoy (or simply the only experience your schedule/budget allows) then you're probably going to find Mariano's a refreshing departure from what Chicago typically offers in that category.
There are other comments above that address prices, but I will say that last night after visiting Jewel (across the street) directly beforehand, the standard shelf prices of most items at Mariano's are almost universally lower, sometimes considerably so -- though the sale (Preferred Card) prices at Jewel were typically discounted more deeply than any of the sales at Mariano's. So if you're a shopper who focuses on purchasing only discounted items, Jewel probably wins, price-wise. However, if you are coming in with a pre-set shopping list, you'll almost certainly do better at Mariano's. Or you could spend your precious evening free time visiting both, like me.
What wins me over at Mariano's is the variety and pricing of local produce (for a supermarket), the clean and friendly atmosphere, and some of the shopper-friendly touches that make it a more pleasant shopping experience than a typical supermarket. Many of those touches are explained in previous posts, that last night I was quite pleased to discover the $8.99 "pick your 6" pack in the walk-in beer cooler (since most of my recent LTH posts have mentioned beer, I'll continue that trend). There were shelves and shelves of individual bottles in multiple varieties from Two Brothers, New Belgium, Capital Brewery, Stone, Brooklyn, and countless other other microbreweries and imports. Just pick any combination in the pre-provided generic cardboard packs, and you're set. This isn't a unique concept but I've never seen it offered and executed quite like this in the supermarket context.
So while Mariano's doesn't necessarily replace any of the other stores in my rotation (Harvestime, Gene's, Jewel, Strack & Van Til, etc.), my trips to some of those estabilishments will be less frequent/necessary. To me it's a very welcome addition to the NW side and I look forward to visiting semi-regularly.