I used to work with them for an internal project, so they did most of our graphic design needs as well which was very helpful since we didn't have much experience in that area at this time! They were really great to deal with - friendly staff who made sure everything went smoothly through out my stay there (including payment).
There's nothing too negative about working or communicating via their site/app; it all worked pretty nicely together without any issues during those times when things weren't quite finalized yet by me personally but still needed approval from higher ups before being released into production phase(s) :) My only suggestion would be maybe adding some more options within their app itself like having different font sizes etc., even though you can change your settings if needbe once logged onto the website and using one account across both platforms ;) Overall not many problems encountered while dealing.