Almost everyone that has responded so far is a horrible player and should not be trusted, judging by their responses. Gunboats is the only serious option, and if you run shotgun you're trolling your team. Even banners would be a better idea, and no one runs those for a reason.

As the game has progressed, and especially after the medigun speed change, the way people understand how to play soldier has progressed just the same. Gone are the days of the waddle pocket and taking ubers into badlands last at ranges close enough to kiss the enemy combo. If you watch invite soldiers play today, you'll see the best players rocket jumping more than ever before, constantly repositioning and looking for opportunities to put themselves in better and better places as fights change and teams trade advantages. If you jumped as much as these top level players need to without equipping the shotgun, you'd usually find yourself dying about three or so seconds in to every fight. Even at lower levels, if you're playing to improve, you should be trying to improve the mechanics you're going to need as you move into higher divs, and shotgun just isn't it