That is not to say Menards can't be as good as the other two... it probably is as good, or better
It isn't. Menards is cheap. For some products, that might be what you're looking for, but others not so much.
The constant slogan is "save big money at Menards". Not the slogan of a quality-driven company.
Agree 110%. Especially true for tools - house brands for Menards and Home Depot aren't even close. Menards likes to bully municipalities around. If they don't get their way, they threaten to close up and build in the neighboring town and leave a giant empty store in its wake. While not likely unique to Menards, they've also been in trouble for numerous environmental messes as well. Avoid them like the plague for any car care products.
Menards does have a few pluses over HD - lighting and electrical parts, landscaping materials, and lumber (just be sure to inspect it before you drive away). They also have a small mattress department -- mostly Serta products they have made especially for Menards.
As for Lowes, it's hard to say...they don't have any stores in the Madison-area (but they sure like to advertise around here). The closest one is 65 miles away. We do enjoy browsing there, but I honestly can't remember the last time we bought something there.
Employees are interchangeable idiots for the most part...3-way tie in my book. If you want any real advice, go to a neighborhood hardware store.