While you're talking to them about getting you a decent room consistently, I'd also talk to them about getting a better rate on the weekend. My guess is they'd rather keep you than lose you to another property.

PS - If you find cheap rates on 3rd party websites, remember that booking through them won't get you the points. You need to book through Marriott. Note, this is different than using 3rd party website rates for LNF comparisons.

Cheers.