We've stayed there four time so far. It's super hilly and since the units are individually owned, the state of repair varies widely. StudioSXM has always been excellent. Our first few trips we stayed at resorts.
Mt. Vernon is completely different, you are really on your own. I suppose negative type reviews are from those who want a more resort like experience. Also, did I mention the hills? I cannot overstate how hilly it is.

We like Mt.Vernon for a few reasons: we love the french side, we enjoy grocery shopping for unique things, preparing some of our own meals is fun, orient beach is the best, we have a circuit that runs between Mt.Vernon and Club O--our entire vacation takes place in that circuit so that we maximize beach time, the pizza at Mt.Vernon is really good, the pool is perfect for a late night dip. I could go on but just pm me if you want more info.