Thanks I was thinking along the lines of a x749 which gives me AWD and AWS, but are there any problems or issues with AWD such as expensive repairs?
As I mentioned before, with both the X749 AND the X748, what concerns me is the full time AWD. There is no disengaging it, ever.
Each front wheel is controlled by it's own small hydraulic valve. It automatically adjusts wheel speeds in the turns, so it doesn't scrub. The problem I see, is down the road, if these valves ever become out of sync, or gummed up, or just plain fail, you would have to basically rip apart the entire axle to fix the problem. I have no idea of the real cost of this, but if I had to guess, I wouldn't be surprised if it would cost a guy $800 or close to it. Shop labor is crazy nowadays, and anything John Deere costs way more then it is worth, because its John Deere. Those control valves for each wheel are likely $300 a piece.
Now, is it common? I have only read one thread about someone having problems with there front tires scrubbing. Out of the hundreds and hundreds I have read about X748's (I was previously going to get one, so I did the research, now I am going with the X540 or the X740) I have only seen one thread pertaining to any trouble with the AWD system.
However, that doesn't mean there are no problems. As with anything, there could be a mass of unreported problems, not ever X748 owner is on a tractor forum or posts there issues.
Personally, for me, I would choose an X740, and have no worries about front wheel motors, valves, or rear steering.
Your needs differ greatly from mine, as I have no hills to contend with, my yard is just a bunch of flat ground. Maybe your local dealer could bring out a few test units so you can try them out on your property, and then you know for sure what's right for you before you sign on the dotted line.