As David Sparks writes in another post, "If the dream team couldn’t make it work, who can?"
In his post about why they are shutting down their popular notes app, Vesper, John lays out what might have been. It should be required reading for any app developer or app startup company. Even with three accomplished developers, success is hard and every decision can make a difference. John also has some great insight into what they might have done differently. For instance, he feels they should have built a Mac app first. We typically think iOS first, but that may not always be the best route.
Vesper, Adieu by John Gruber