I just picked up a new X748 with the 60" 7 Iron deck about three weeks ago. I sold my X595 with the 62" deck with just under 750 hours.
I mowed once with the new deck and my initial feeling is that is gives a better cut than the 62C deck or the 60" that was on my old 445. Its also noticably quieter. The gearbox has much less of whine than the other decks. Again, I only mowed once and the grass was dry but there was no accumulation of debris (sludge) under the deck like the others. The wide open design without rivent heads and other obstructions to catch the debris I think helps. Of course it is a new deck with perfect paint so we will have to see how it performs next year after the paint has been roughed up a bit. I had basically the same deck on a 4300 compact utility ten years ago and was quite impressed even after two years of mowing how clean the underdeck remained.
I was a little nervous driving over the deck when I took it off last Saturday. Somehow it just doesn't seem right to drive a tractor up and over the deck but it worked just fine. I won't be putting the deck back on until next spring so we will see how the installation works.
My initial evaluation is that the X748 is quite a trator albeit expensive. My old X595 was essentially trouble free after a couple of very minor issues when I first got it. The 748 is full time 4 wheel drive so we will see how that holds up over time but the new ones come with a 700 hour 4 year warranty. It seems to take a little more effort to hold the foot hydro control in position over the old tractor. I suspect it is because the oil has to be pumped to the front hydraulic motors which requires more hydraulic pressure. Its not annoying just noticable. The big advantage of course is that the 4wd is on all of the time and there is no front tire scuffing. It also turns just as short as the 595 in two wheel drive mode. Deere did a nice job on this design. We will have to see if it holds up over time.
I will be putting my heavy duty 60" sweeper on this weekend that I picked up this summer. When we get the first snow I will be anxious to give it a try.
Now, If Deere could just redesign the front of the tractor so it wasn't so darn ugly. They could just ask the folks who designed the 3000 and 4000 tractors to give them a hand. I guess I can live with the looks as long as it remains a great functional tractor.