The reason you want to go with continental is because you can snap down on the ball and create that extra racquet head speed, or you can add a lil spin to give the flat serve a lil more consistency... You can't do that with an eastern grip; try to snap down on the ball, the racquet butt gets blocked on the wrist.. James Jenson's serve video demonstrates this FACT!.. If you're satisified with your serve, then continue to use the eastern grip.. Later when you want to add a faster flat, or want to add some spin in that flat serve, you'll see continental is the way to go..
Lastly just because it is consistent for you doesn't mean you shouldnt strive to do it the right way. There are advantages when you do it the right way.