The store is pretty good for homeowners, not so good for contractors. But the reason for a so-so score is because the online inventory for the physical stores almost never matches what they really have. I've purchased online to try to save time, and when I show up to pick up the order, sometimes as much as 1/3rd is back ordered, even when I show them it was listed as in-stock at that store, they just shrug their shoulders.
Little tip, if you buy online from your local Lowes, call ahead to make sure they have your entire order before you waste a trip. If it's a small order that you don't need right off, just let Lowes online deliver it, save you some frustration.