Ok, well I'm about your same height and weight and shoe size... I'm 6'3 250ish and a size 13.
I ride a Rome Flag 168 and love it. I came from a Ride Decade Wide and before that a Ride Yukon. The Rome has a bit more pop than the Yukon which I found to be a bit too stiff even at our advanced sizes... Don't get me wrong, the Yukon was awesome but I just like the handling characteristics of the Flag better. It's fast as shit too, when that thing is fresh off a waxing I keep up easily with my lightspeed skier friends on the slopes.
I equate the NS Titan to the Yukon as I got to ride my buddies at the end of last season. Great, solid board but super stiff. If you were going to be doing strictly steep and deep gnarly lines than for sure the Titan is the board I'd go with. For all around mountain riding and great pop in the tail I'll take my Flag any day.
Another board to consider is the LibTech SkunkApe BTX... I'm taking a look at this board as a potential addition to my quiver either later this season or for next year. This board is a bit more freestyle oriented as it is a true twin and it does come packed with great new tech like MagneTraction and Reverse Camber which will help hold the edge in icy conditions and float a bit better in the pow among other things. I can't speak on this boards performance yet since I haven't had a chance to demo it, but I've only heard good things.
Personally I really like my Flag and even if I get the SkunkApe, the Flag will still be my everyday board because it inspires that much confidence on the mountain. It is a huge jump up from what you are riding now for sure and can stand up to most gnarly of the gnarly conditions that you'll get into.