The difference is... they offer nothing except "we made something, sign up?!" whereas this is actually a lot different. If you read the thread, the founder is in here commenting and you can tell that there's already a working product. Polished and shiny it may not be, but this is not just empty space like most LaunchRock type pages.
First difference doesn't even count. With no offense to the founder, its easy to take part in the discussion.
How can you tell that there is actually a working prototype/MVP? These wireframes can be made in proto or PSDs.
How is it a lot different? If I click the misleading "Get app" button, it shunts me down to the email capture which says that even the early subscribers won't get anything for three months.
I don't think the fact that the founder is commenting is relevant. I could chat with people about a theoretical or in-progress product quite easily.
I've flagged this submission. However much work has gone into it, GP is correct in saying that it's an email sign-up. Better for OP to wait until there is a product for people to use.