Depends on what you value. I've stayed at the following Nola Marriott properties, as a LT Platinum:

• Marriott on Canal - one of the truly better lounges I've seen for a domestic Bonvoy property, really good breakfast spread. Massive property, decent location on Canal, rooms if I recall correctly are more or less standard Marriott fare. Wait for an elevator can be a thing during peak hours. Worth repeating, though, the lounge is fantastic.
• JW on Canal - Yes, slightly more upscale than the regular Marriott that is more or less across the street, rooms slightly nicer, smaller prop overall. Lounge is OK. Rooms are nice, seem to be in decent condition. Crawfish fritters from the bar restaurant are really good.
• Le Meridien (stayed while it was a W many times as well) on Poydras - No better location if you want to hang out at Harrahs. Most recent stay was ~4 years ago. Rooms showing some wear.
• W FQ - Great staff, nice quiet FQ location. Rooms seemed very dark (I know, hotel rooms aren't the place to look for well lit areas in general), even by hotel room standards. Also showing some wear (as of Dec 2021).

Overall, I would probably rank the Marriott on Canal #1, primarily for the lounge. Combined with generally cheaper rates, it's a bit of a no brainer for me. I find many of the New Orleans hotels (beyond Marriotts as well) to have led some pretty rough lives - say "10 years of average wear in another city in 5 years" sort of thing. No doubt many an epic party has been held in those W or LM rooms, and it shows. Lastly, unless you get out into the arts district or elsewhere, the above props are all within a 10 minute walk of each other so I'd say they're nearly a wash in terms of location, unless you are the type that views walking as an unpleasant chore. Hope that helps.