In my experience so far, there is definitely a meaningful difference between Walmart+ delivery and curbside pickup. I've had very good experiences using curbside pickup since mid-2020. By and large, my curbside pickup orders have been punctual, accurate, and brought out to me by friendly people. The three W+ delivery orders I've placed over the past few weeks have been very hit and miss, however. One time an entire category of items (bread) wasn't delivered, yet I was still charged. Both other times, items that were listed as in-stock when I ordered did not get delivered. I've tried ordering the same bottle of olive oil twice now, and both times it's been listed as in-stock, yet becomes "unavailable" shortly before the delivery arrives. This never (well, very rarely) happens with curbside pickup. So, IME, something about the delivery process is fundamentally less reliable than the curbside pickup process. Once my free trial is over, I'll happily go back to picking up my orders from the store.