I prefer my local Ace store to the big box hardware stores every day of the week. The customer service is superior. Sometimes I'll go to Home Depot and I'll have to search out someone to help me, and half the people there I wouldn't trust beyond pointing me to an aisle. At Ace, it's a different story. When I talk to one of the dudes there I feel like I'm talking to someone that knows his stuff. The workers there have that look too....you know.....they look like the guy on your street that will come over and help you fix your furnace or a leaky pipe. These aren't salesmen. They aren't customer service associates. They are just dudes that know how to do stuff, and they'll tell you how to do it - but only if you ask.
And for what it's worth, even though it is a small space, I've yet to go in and not find exactly what I needed. I can't say the same for Home Depot.
Pros: customer service, reasonable prices
Cons: early closing times, small store