The best thing about focus pdm is that they are always there for you with your every request which makes their service so great because it's not just another one out here who will do anything at any given time without asking questions first! I really can't think of no downsides as everything has been perfect thus far since we started working together but if i was asked then maybe this would be something :).
They have helped us develop our products by creating new designs using different material like plastic/metal etc.. Also when needed help integrating them into other platforms such as iOS app store & android market place.