This is what I've decided to do after researching and reading everyone's comments - I am just waiting to line up enough MR points for a Cat.5 travel award and then I'll likely shift some of my stays over to SPG - I also need to time it so I can snap up the SPG Amex and meet the spending limits. My work travel will continue to (mostly) be Marriott, at least enough to maintain status, while I'll toss and remaining stays to SPG properties that exceed what I'd expect to get at FS Marriotts. That's the plan at least...