Like others have said, the longer cruises really help one decompress. The Journey cruises do offer extra activities that make them a lot different than the non-journey cruises. I thoroughly enjoy them.
However, one thing to note is that the ship will load all of its provisions (food and drinks) from the home port for the whole two weeks. They will run out of certain items as the days go on. By day 12 or 13 expect the omelet station to have very little to add, expect certain beers to run out, etc. There still will be plenty of food, just maybe not your favorites. If there is something you really want, get it early in the cruise because the ship might be out if you wait.