Haha! Well I was really kicking around the thought of picking up a 501X, but again, I'm a firm believer in tubs for dirt (and addicted to stick pack lipos...) The overall cost is pretty similar to a 501X, so if you think of it as buying a 501X with a carbon reinforced tub chassis, then it's easier to swallow than building a Durga with 501X parts...
It did take me a few hours to download the instruction manuals/parts lists for both cars and sort out the option wishlist along with the necessary stock components.