I like that they are very flexible with their pricing structure so you can get exactly what your looking to achieve within budget constraints! The team is fantastic - always willing help out when needed as well have some great ideas of how things could be improved or made easier in future releases!! They're also really good at keeping an eye open about new technologies which may benefit them down stream too (such us React Native).
There's nothing i dislike but if there was then it would probably just come from personal preference rather than anything specific against D&T themselves :) As mentioned above though we've been working together since early 2016 now where our products work closely alongside each other day-to.-day meaning communication has become much more efficient between both parties without any problems arising.