I kinda sat this one out. I don't know what you already had, and what the budget was. I woulda said, go Marauder all the way, and add in the tank and stuff, IF you already had a springer.
There have been several well-documented Marauder issues in the past, mostly in the early production runs (I have #39 and there is no problem so far). The good news is the backing you get from Crosman, so I wouldn't hesitate on this, and I will probably get another one in twenty-five just 'cause. Plus the pistol.
They are famous for shipping with "dirty" barrels, which is probably preservative. Not a defect, and easily cured with Goo-Gone or cleaner of choice, swab dry and let stand before shooting. I am still amazed whenever I shoot the thing. I only shoot CPs throughthe .22and it is ridiculously accurate and quiet. As I often say, it doesn't replace my springers, it supplements them, and I love both. I am really happy with the 4500 psi cf tank (Joe Brancato) even though i choked on the initial investment. If you really want to spoil yourself, a Marauder and the tank are a good way to do it.
R9s are nice. Do y'all think they are that much better than a tuned B-26?