1)you will get your flavor / spice profile in between the bone and main meat. As we all know the spice will only travel just under the surface, it never will penetrate no matter how long.
2) this also helps the flavor on the bone, which in my opion is the best part. Getting that salt in the middle really kicks it up and it is ready to go once out of the cooker.OR you can place on the grill for another sear..
3) when you do this ahead of time, especially when you have 2 or 3 large roast going on, it will help you serve your guests. You will be able to slice any size you want or location for doneness... and when people ask for a bone in, you can neatly place along side the main piece. Now when the first one is done being sliced, you can have an instant start on the next one.
However the size of the roast, even a two or three boner this is how I prefer to do it, but if you have 150 or 200 people to serve and you are the one standing there with the peoples plates pointed at ya you have to rock and this gives you the best chance to keep the line moving...with the best flavor they will ever have..
Also, I will have a grill going at the next station for the people that want a quick sear, or a well done piece..
Give it a try, you will NOT be dissapointed....
TwinTech Pro Double, Backwoods Fat Boy, TwinTech Hawg Kooker, FE 400, SP SPK 700, Empty check book and understanding wife...sometimes..