I have both a Deere 455 AWS and a 2007 Deere X744 AWS, and will agree that the improvements on the X700 series are very nice, especially the Hydro Petal set up, side by side, also I really prefer the deck height adjustment set up on the X700's vs the 4X5 series. Still, I really like the 455 as well, its easier to get to the rad on the 455 to clean out, then the X744. I really like the one piece hood on the X700's, but find its a pain to remove the side pannels on both sides of the rad on the X744 to blow out grass clippings and debris.
Its easier on my 2305 to blow out the rad then the 744, but thats just my observations. Still I love my 07 Deere X744, which I bought last June with 692 hrs on it, and currently has 803hrs on it. I have been using the 2305 to cut grass as well to keep some hrs off the X744.
Take Care Jason B