Very easy to set up, really great documentation and very good support! I didn't have any problems with this extension when implementing it in my store. There's a possibility that I could see some issues, but nothing major has come up so far. The only thing I can find is the fact that it's hard to manage all the emails and messages in one place.
If you know what you are doing then there shouldn't be any problems. We use webpush for sending our customer newsletters and promotions. This also…