We had FP+ last week, on Tuesday April 28. We were on the side in front of Crystal Palace. It was GREAT!! NOT crowded at all. We did put DS in the front, behind the fence, in his WC. But, when ELP came by, we went over to watch that on the side. Another guest had said, GO ahead, leave the chair here, I will watch it. (DS can walk for short periods). After ELP, we went back to the WC.
I would absolutely do this again. We never stay in the parks for the fireworks, because of the difficulty with the WC, and I get frustrated trying to see the castle projections dealing with the whole "kids on shoulders" issue. Even that was much better, because right in front of the fencing, the CMs keep it clear as a walkway, so no kids on shoulders are RIGHT in front of you, they are 8 feet away at least.
We did stay in the front of the FP+ area, but on this night, people did not crowd the front, they were pretty spread out. I think most people did stand, not positive, as they were all behind us. Other families near us had family members with behavior issues, mental or physical problems that made this FP+ area a huge bonus.