I finished running this about a month ago. Took about a year and 4 months playing almost every weekend in marthon 6-10 hour sessions (with a month off). We started it during the magazine period so we didn't run Drakthar's Way. It was a lot of fun. I ran it for only three players playing 2 characters a piece and unfortunately one of them couldn't play anymore so we finished with only two (playing 3 characters a piece). I integrated "Chamber of Antiquity" and "Root of Evil" as side quests that allowed the PCs to discover more about the villains in SCAP.
Depite the fact that it was a pre-written campaign, I spent a good 4-5 hours a week doing prep work and reworking of the campaign. Not that it required it, but I really enjoyed personalizing and editing the campaign for my players. That's what the campaign's biggest asset is: There's so much material there that it's easy to flesh out for your personal style.
If I were to do it again:
I would make it take place over 10-20 years with about a year or so between most adventures. The timeline of the game was a little to condensed and it didn't really sit right that a character could go from 1st-20th level in about a year. This could also set up villains and Cauldron really well.
I would wait until the Savage Tide comes out. That map of Sasserine would have been useful. In my homebrew (semi-Greyhawk) world, Sasserine was a port city that a couple of characters came from. Unfortunately, I had to make up most of the details off the cuff so it never felt right to me. Most mysterious characters from far away came from Sasserine.
I would run more sidequests. This could also allow me to let the characters "come off the rails" a little bit, but still be able to rope them back in. Some of the recent dungeon adventures would really fit well. Mad God's Key. And Madness Followed. The one with the disaster happening to the city (high level). Maybe The Quicksilver Hourglass instead of Asylum.
I would not let people play more than one character. This wasn't as bad is it could have been, but it definetly impeded role-playing between characters. Some characters that people ran could have been really interesting interacting with each other, but because they were run by the same player, role-playing was kind of akward. Also, a lot of wealth distrubiton (loans) happened betweened characters which may have thrown off some balance. However, they did RP the loaning and all that so I guess I can't complain.
The player's favorite part, strangely enough, was the dungeon crawl series of Life's Bazaar, Flood Season, and Zenith Trajectory. After that, they felt they didn't have any idea what was going on or what to do until around Soul Pillars or Lords of Oblivion. Some of this probably due to the fact that most of the super cool information was being fed to a secretive player who (unfortunately) didn't last till the end of the campaign and thus, didn't get to leak said information. I might consider dropping or severely reworking Demonskar Legacy, Smoking Eye (my players HATED the random encounter table as they walked across the plane) 13 cages, Shatterhorn, and Asylum. This has more to do with my personal tastes and I what I feel would fit for the characters than anything wrong with the adventures.
I would highly recomend this AP. It was a ton of fun to run and players had a great time playing in it.