The Designer's Augmented Reality Toolkit (DART) was an augmented (AR) and mixed reality (MR) authoring tool targeted at new media designers. It was released in 2003 and was heavily used by a diverse population of creators for the next several years [31]. Ten years later, we approached a group of users to collect reflections on their use of DART, the artifacts they produced, their subsequent AR/MR authoring, their thoughts on the challenges of AR/MR authoring in general, and the state of modern tools. In this paper we present the findings from in-depth interviews with these DART developers and other AR experts. Their reflections provide insights on how to successfully engage non-technologists with new media and the challenges they face during authoring, the unique requirements of new media authoring, and how modern tools are still not meeting the needs of this type of author, highlighting where additional research is needed.