A long time ago, I wrote the attached post
on a dedicated Marriott trader -- I think for the most part it still holds, and please excuse the passage of time on MFs and similar "antiquities". I hope it is useful.
For you, I am extremely curious how the new Vistana preference plays out -- if Vistana's preference is pari passu with Marriott's and not a secondary preference, then SDO just became a very powerful trader. You're already familiar with it as a Vistana trader, now imagine leveraging it across Marriott's larger network of properties. I own an SDO 1-52 for other reasons (Spring Training) but it now has trading potential as well. It will take some time to figure that out -- and I will run a few trade power experiments to see how it does. I have two dedicated Marriott traders (Shadow Ridge Enclaves and Willow Ridge) and will report back to TUG on how the SDO did versus those too.
I'm not sure I would buy anything new right now, because trading world is in flux. One of the things I love most about TUG is that we find the opportunities in the different systems and we share them (and maximize them).