I was in the same boat as you buddy! I went and test drove the QX56, Tundra, Ram 1500, Silverado. I also test drove quite a few cars but settled on a truck, the Ram.
The Tundra, that is one rough truck! It's nice by all means, BIG too. But I took it over this road that I have driven the Titan on many many times (gotta take this road to the highway) and it's kinda beat up. The Tundra..all over the place. I think they replaced the shocks with metal sticks because that truck felt even the slightest bumps. The Titan (mine) would go over the same road and feel only half the bumps. Mostly the bigger ones. The smaller ones I'd just hear creaks and cracks of the frame/body tweeking around. The Ram, same road, only felt 1/4 of the bumps. The ride was just slightly rougher than a luxury car.
Power wise, Titan hands down!..but for city driving. The throttle response on the Titan is instant..the Tundra and Ram there is a slight delay. And I also noticed on the Tundra (had 1/2 tank of gas), I went around a 90* corner at a stop light. I hit the gas, went to drive around the corner and the power completly cut out. I gave it more gas and it when the power came back on, it jolted forward..now I'm not sure if this was traction control or something worng with the motor? With the Ram, it's got power, just like the Tundra and Titan. However I took it on the highway, doing 60mph, and I slammed on the gas..MY GOD that thing hauled azz! It deff has high end power. Low end I think it'd give a Titan a run for the money but the throttle response kinda sluggish..
Interior, the Tundra..kinda ugly. I think it's too bright with all that silver. And the nobs. The stero is kinda far away to reach. I'm 6'4 so a tall guy with long arms and I found it kinda hard to adjust the stereo. I had to lean forward just a little. The Ram 1500, interior was laid out nice. Lots of storage and if you get a SPORT or Laramie they are especially nice with the console shifter. And the stich work on the leather dash, seats, console is a nice touch.
Overall I looked for these main things: Looks, Power, Ride (rough < smooth), Detail, Warranty. I picked the Ram over the 09 Titan because of the interior, smoothness of the ride, and the lifetime powertrain warranty. Plus a little of it has to do with the fact I've had a long list of issues with the 04 Titan.. And I currently own a 01 Ram SPORT and only one issue in 70k miles..so that also had a lil imput as well...
But if I didn't have any issues with my Titan..odds are I wouldn't be looking for a new truck. And if I was, it'd be a very hard choice between the Titan and Ram!!