If all you are doing is cranking off rounds aimlessly, shooting in general can be boring. Can you boringly and consistently put rounds through the same hole or fist sized groups from 3 to 25 yards? I can't yet, but I'm getting there and that's what the 9mm allows me to do on a regular basis, save money and practice. I enjoy shooting both calibers but I shoot 800-1000 rounds a month in pistol alone, and the 9mm allows me to continue to train at that level.
For God and the soldier we adore, In time of danger, not before! The danger passed, and all things righted, God is forgotten and the soldier slighted." - Rudyard Kipling