Finished reading the adventure last night. It's very, very good.
I would say hands-down better intro to D&D than Dragon of Icespire Peak. It consists of a home base, three adventure sites, and three "random encounters" to be used when traveling around the island. All three adventure sites are much more thoughtfully written and fleshed out than anything in DoIP, and each site has an interesting story and the roleplaying opportunities across the board are much stronger.
I'm not sure if it's better than Lost Mine of Phandelver. I would have to run it. It does some stuff better - more role-playing opportunities, better NPCs, richer story. But Lost Mine of Phandelver makes players feel like they have completed a mini-epic and gone from level 1 to 5. Dragon of Stormwreck Isle will make players feel like they have done three pretty self-contained fun adventures, met some cool NPCs, and seen some neat stuff. It's probably 4 4-hour sessions, whereas LMoP can easily take 10-12 4 hour sessions.
The third and climactic adventure site in Dragon of Stormwreck Isle is the weakest of the three, with a BBEG who could easily get curb-stomped in one round by the recommended 4-5 level 3 characters, particularly if they roll well in initiative, and an interesting ritual set-piece combat encounter that, as written, most players would never see since they'll prevent it from ever starting. I suspect a lot of DMs will be tweaking this chapter to offer more of a challenging conclusion. The two earlier adventure sites are both really, really good.
I would say that Dragons of Stormwreck Isle is a good enough adventure that it's worth the price of admission on its own. If this was your first D&D adventure, you're probably going to have a really good time.
