This adventure is a very straight forward, well paced delve and heavily combat orientated - what I think a crawl should be. In saying that, there is a need for a very well balanced party to succeed. I played 1-2 and was personally awed by the last act.

This is a great adventure for beginning characters or to introduce players to PFS/PFRPG. Particularly good for getting power players to realise that there is more than optimising characters and that they know all that there is to know in the game.

A very generic "Fetch me my MacGuffin" dungeon crawl. Filled with deadly encounters and awful maps, this doesn't rank very high. The amount of roleplaying is close to naught. After the briefing it's just walking through a railroad under the city, seeing the wonderful sights of the sewers.

Last encounter is really some shafting. Most likely will make at least one player just leave the table to read a book or something, unless he/she is sadistic.

The adventure doesn't have a lot of RP built into in (though there is some if the PCs go out of their way to make it). On the other hand, the way the scenario is set up, it makes sense that the PCs will be fighting their way through this.

The entire time I ran this scenario, I felt the encounters were far too difficult for a group of characters of the first level to deal with and the adventure constantly throwing copious amounts of Cure spells in the form of a myriad magic items did little to offset the disproportionately powerful creatures the players were pitted against.
A specific encounter in which I felt that the players had little chance to survive without the DM's intervention:

I’ve run this four times and I still don’t get a lot out of it as a GM. The players haven’t complained though so it’s not one I’ll avoid running. The scenario misses a great opportunity to flesh out the Absalom wizard’s college known as the Arcanamirium. Instead the PCs are hustled into the sewers with a very thin story from an NPC most players would rather beat to a pulp than assist. The maps are another disappointment. Paizo might believe they are helping out by using their Gamemastery line of map packs instead of creating original maps for the sewers. It’s a matter of opinion in my case, but the Sewers map pack is shoehorned into the scenario. The combats are balanced however, although the high tier faces a very tough fight. The faction missions are a letdown, more of the ‘find this item/item found on/near bad guy’. The item access on the Chronicle sheet is a step in the right direction, but I think allowing only a single purchase of an undercharged you’ll-find-out is being too miserly.

This module was fairly straight forward hack-n-slash, but definitely fun hack-n-slash. Very little prep work would be needed to run it straight from the boxed text.

The storyline was interesting, but linear and not necessarily engaging. While fighters and healers are needed, beyond the ability to do damage other classes are not required or utilized. There was minimal role-playing and no real traps of which to speak. Combat was varied and involved a some terrain challenges. Monsters were setting-appropriate and the appearance of a new aberration added to the enjoyment. Some faction quests seemed a little disconnected from the story, asking players to track down random items for reasons unrelated to the plot or meta-plot.

Overall, an enjoyable, solid module that most players will enjoy. Not the module for role-play intensive groups or players who want an involved, detailed story.