Two words:

Electronic throttle.

My 2000 was faster than my 09 truck, but I had to spend lots of money and time to get it there. Even after all of the mods, it was only slightly faster than this truck is bone stock.
Once a programmer comes out that will get rid of all the torque management and fully disable esp, your 09 will smoke your 07. 50 more hp and less weight.

 

What you feel is what you feel, there is no denying that. I had an 04 Hemi all stock (3.55 geared 4x4), same HP as your 07 and it was quick to be sure. When I test drove an 09 with the 3.55's I too felt my 04 might be faster out of the hole but it was hard to tell becuase my 09 drive was so brief. After owning my 09 for a few months I now know my 04 would have gotten beaten badly by my 09. My wife said it best "compared to the 09, the 04 felt like a dog". Thats what we both feel comparing the 2. If your 07 is as quick as an 09 I would not even bother trading up to one - you already have a screamer. As an aside, the 3.92's make a definite difference, you made the right choice. Congrats on your new truck and let us know how you fell after driving it for a while.

 

Congradulations, to bad you can't go drive it off the assembly line yourself.