Pros: Most everyone that I DM with or play with knows about this module. It starts off very simply with players being roped into an investigation that they need to conduct on an island out of town. One of the things I've always loved about this module is it does a good job of introducing new characters to the season(whether they are recurring or not) and allows players who remember NPC names/roles from prior missions are allowed to tap those new sources to gain some insight into what's going on in this module. By the time the players actually reach the island there fun really begins as they are pretty much open to going in whatever direction they want to and will still end up fighting in the most memorable of the module's encounters. Also, 'The eyes' is a good thing for a mad-man to say over and over to scare Tier 1 players into thinking they're going to be fighting something well beyond their character's ability to handle. The first game-store I went to ran this module almost every-other week as either a stand-by table or a regular table as it's simple enough that new players can jump right in and begin learning how to play DnD while still being able to keep up with the plot.
Cons: Time. I have never actually run this module in under 5 hours. Part of the reason is that I want to give players the choice to explore the island as they see fit and there is a lot to see there and a lot to investigate. Players can spend an hour role-playing in various parts of the island, learn almost nothing useful, and not advance the plot much without some DM prodding which can be good or bad depending on how you like your games. DM railroading may be necessary if you are on a strict timeline for this module.
Verdict: 9.5/10. It's memorable enough that even though it has always taken me longer than the alloted time slot it's nearly perfect for DnD. Would buy it again in a heartbeat.