Purely anecdotal, but I found Lowe's generally had much better customer service. But maybe it's just where I live
I’d agree though, it’s department dependent. The electrical at my HD is an unorganized mess, but their plumbing section is world-class. Lowe’s is oddly flip-flopped. To Lowe’s great credit, their staff has those little tablets with inventory locations on them including all the top-shelf and end cap locations the website doesn’t show. Those usually save my trip, HD doesn’t seem to have an equivalent.
I've found it to be very datetime dependent. I walking the aisles on a late Sunday night recently and the only time I saw an employee was at the self checkout before I left.
That’s damn good customer service right there, if you ask me. The fake-chipper act makes me want to dive into a wood chipper…
The old lady that always seemed to be behind the register eventually started greeting me by name when I walked in. (I don't recall ever giving her my name; maybe she remembered seeing on a credit card or something.)
After the pleasantries (which didn't seem fake at all), one of the greybeards present would appoint themselves as my personal shopper. I'd go down my list of demands that was only vaguely sorted by department: "One M8x1.25x80mm all-thread stainless Philips screw, a 16x20 furnace filter, a box of #8x3/4 sheet metal screws, and uh... what do you have for can openers?"
And then we'd make a lap or two of the store to get these things, and I'd pay and GTFO.
It was great.
But for actual help and humanity (if you can afford the price and the more limited selection), Ace is consistently better near where I am.