I like the idea of modularity, especially with a camera that's supposed to be small and light. You mount the grip for comfortable shooting, and remove it when you're cutting grams and bulk.
It's better than having to buy two cameras or, as in my case, making a sacrifice with only one camera body. I chose ergonomic priority for my camera, but it costs me nearly a kilo in life-support equipment every time I bring it, compared to something smaller like the DP1M.
A big studio camera with poor ergonomics, on the other hand, is just crazy.