First, congrats on the product as I don't want to come off as being a bowl of sour grapes when that's not the case. I totally dig the concept of immediate results for changes made. Like I said in my OP, I'm approaching this from the viewpoint of a team of more than 1 where there are multiple environments to account for so that's my starting point. For a very small team / personal site built using Rails that has no development environment I can definitely see the usefulness of this product.