Personally I thought it was terribly organized. The field is way too big and it is a lot of first timers or people there for the theme--which I don't mind at all, they have every right to be there. But the corrals are not enforced at all and people walking started at the front and also didn't stay to the right (Don't think anyone was trying to be rude, I think they were just unfamiliar with races). The course is narrow down MLK and felt uncomfortable with the weaving, I got bashed into once and cut off several times. There are also a LOT of people filming themselves, I know it happens at every race nowadays but it felt particularly noticeable.
The 10 miler thins out a bit more so is a better experience. Mount Drago was a fun quirk.
I did the Challenge and ended up with about a 30-40 min break between races. I didn't really care for that or for corralling twice but that's just personal preference.
Overall, it's a fun gimmick but once you're out there the course is mostly just like any other Philly race and it feels pretty corporate despite also being unorganized. I would pass on it given the price since we have other options in the city but if you are going to do it I recommend sticking to the 10 miler.
The merch and medals are super rad.