What concerns me is the time they spent on the software before even going into the beta phase: "Coda 2 has now been in development for about a year and a half."
This is probably normal for the traditional development cycles(, which is not what I'm familiar with). However, with the web apps fastening the whole process, they will face serious challenges. A good example is CulturedCode's Things[1], a good GTD software with no support for cloud syncing. They wrote a series of blogs about how they will implement it back at the beginning of the year. After roughly 9 months, they haven't finished it and it is still in internal beta. Even for the beta, it has been 3 months. I can't imagine that for web applications. Things was great, but because of the pain of syncing, I switched to Wunderlist.
Panic makes great things, hopefully they will keep it up.