This design option encompasses stationary and mobile carts. The theory on this is that the saw and the supports are self-contained and can be used anywhere inside or outside the shop with no additional equipment, minus any dust collection.
One advantage to a cart, especially the mobile kind, is that it can really go anywhere in the shop. With a mobile cart, it could be wheeled to a central location if the stock is too long. Most carts have flip up workpiece supports, however I ran across one that had arms that swung out and then down. This design has the advantage of residing next to a tool or cabinet and not have to be moved to use either support arm. The deck of the saw would obviously be above whatever closest bench or tool. I unfortunately do not recall exactly where I saw this, but I’m almost positive it originated in a magazine. When I have that, I’ll post it right here with a link if possible.
Building a cart also allows for a bit more creative solution for dust collection, if one has the room. I’ve seen some with full-on hoods to help contain it. A cart also helps with very long pieces, something that when I go and build a new workshop might be very helpful. However I do not have any flat ground in front of my shop to work with. I would probably be better off temporarily moving the saw to the workbench or table saw to do those mid-piece crosscuts. A mobile cart also means I have to keep a decent amount of room free in the workshop to maneuver. I already have this room somewhat, but the cart would be rather bulky. A stationary cart is pretty much like a cabinet, so unless it was mobile I don’t see much advantage.
For those reasons I probably won’t go the cart route. I am still keeping it an option, though.