I did the inaugural DL half in 2006 and liked it. I stayed at Paradise Pier which was nice because they bumped me up to a suite for free. I was by myself so it was way bigger than I would have paid for but it was on the top floor so the view was awesome.
To be honest if I went back I would save the money and stay at one of the good neighbor hotels. They are within walking distance and since I am the kind of person who just uses the room to sleep I would save the money.
I did go to the parks after the run and I actually did a tour, the Walk in Walt's footsteps tour. If you have never been to
Disneyland you will notice it takes a lot less time to do the parks. The most fun part for me was just spotting the differences between DL and MK.
I know they are doing a new course this year so my experience won't matter but for what it is worth we ran through DL and DCA in the first 3 miles and then out into Anaheim. We ran through the Angels stadium (I think it was Edison field then, who knows now) and then finished at Dowtown Disney.
The course is flat and if you have never done a non-Disney World run it was pretty well run, on par with other long runs through cities. Since it is not all on Disney property they don't have the same level of control.
I was debating doing the DL half this year but am carpooling with some friends to do the VA Beach half and Baltimore Full. The price was better.
One other big difference you will notice with DL depens on where you are from. Being from Cleveland the 3 hour time difference made that 4:00 wakeup a lot easier. You also walk to the start so you don't have to give yourself quite as much time to wait for a bus.
Good Luck and I know you'll love the run if you do it.