I'm a bit late in posting my experience, but here it is.
The Soiree was WELL worth it!! We went on Oct 23, and our party managed to find a spot in front of the rope for the 1st parade viewing. We enjoyed the free water and suckers. I won't bother posting any duplicate photos or descriptions of the myriad that have already been posted...everything looked, sounded, and interacted just as good as what the majority of people on this board have already indicated, and I highly recommend it for those who have not yet tried.
We did make one mistake, though. After the first parade, we left the Soiree view area hoping we could finish up Stage 1 of Sorcerers of the Magic Kingdom. We managed to get through 7 of the 9 villians before it was 9:15 and we tried to head back so we could watch Hallowishes. Unfortunately, ALL paths back to the area were thoroughly blocked off, so there was no way we were ever going to make it.
However, thanks to a helpful cast member, we circled to the side of the castle near Liberty Square in order to view the fireworks, and while we couldn't see the main part of the show, the loud BOOMS of the fireworks literally right next to us were thoroughly entertaining to watch. We could clearly see the launch points and the smoke, and I think our viewspot may have been even better than the reserved area!
We had reservations for the 10:15 party, so we didn't have a lot of time in between, and had to wait at the drop rope before we could get into the Soiree area. Excellent time was had by all, aside from the fact that our assigned spot, Table 17, made it a bit difficult to see what was going on in front, especially the creepy organ player and the dessert introductions.
My only concern was that there was no set line for a photo with the Queen of Hearts. The crowd was all mish-mashy and basically after one photo was taken, the next one was with whomever happened to step up next. If they would exercise more control over this, I give this party a 100% mark.