I'm not sure about the rest of you, but I actually prefer the long courses over the shorter ones any day. Let's compare Midfield to Nürburgring, for example (both ends of the extreme):
For an endurance race of approximately two hours (which most of the endurances seem to be from previous GT's), it would require around 100 laps of Midfield. But only 15 laps of the 'Ring. That alleviates one of the big problems that nearly everyone has with endurance races.. boredom caused by repetitaveness. Doing the same lap over and over and over again. I've had several instances where I've gone three or four laps in an endurance race and not even realized it, because my mind starts wandering.
The longer courses eliminate this problem almost entirely. Eight minute laptimes are the norm at the 'Ring (depending on the car, of course). And consider the end of a lap.. on a short track like Midfield, you could almost blank out and "miss" a lap. You cross the line, and all you're thinking about is how many more laps you have to go. But on a long track like LeMans or the 'Ring, there's a real sense of accomplishment after finishing a lap. You cross the line, and you think "I made it.."
That, and the longer tracks are more challenging. On a short track, if your lap times aren't up to where you want them to be, or you're losing online races, there's probably only two or three spots you can improve your line to shave time off. But on the 'Ring, there's a hundred of those spots. And many of the "tricks", particularly for the 'Ring, are very subtle. Slip outside the "instinctive" racing line that we all follow, and you can suddenly pick up another 10mph coming out of the corner. And there's a dozen places on that track you can do that.
So I, for one, am very much looking forward to the long courses.

LeMans and the 'Ring will probably be at the top of my "Most Driven" list.