So I got myself a metolius double ledge and the fly to match. It is a 4 season fly and has no door. I could see a door being nice sometimes. Who knows if the BD cliff Cabana fly is compatible?
I know Mark Hudon modified his metolius fly so it has a zippered door. That would certainly be a more elegant solution, as the ledges are not the same size. Probably cheaper, too.
If you are going to really need the fly as in if shit hits the fan you will be better off without the door, fewer seems, zippers etc. to leak. I only use the fly if there is rain or snow in the forecast otherwise it stays stowed. I would stick with the original fly.
I agree with most of the comments above. The BD fly is a real pain to use since you have to set up the ledge inside it. Maybe good for a winter route in the valley or somewhere that has less stable weather than Yosemite. the metolius drop down fly is much easier to use/set up and other than not having a floor is good enough for most walls in the us unless its winter or the forecast is bad. I have had both a metolius and BD ledge and the platform on the BD is bigger so I'm guessing the BD fly might not fit the metolius ledge that well. I didn't like the BD ledge (too heavy and hard to set up) so I sold it and got the metolius which I like much better.