The establishment of the Sustainable Development Goals (SDGs) has put the transition to a sustainable society on the global agenda. In this respect, gamification has gained increasing attention as a tool for companies to motivate employees to adopt sustainable behaviors. Specifically, adapting gamification design to the preferences and needs of individual users has been strongly advocated. However, knowledge of personalized gamification design is largely based on conceptual assumptions and self-reported preferences. It remains thus unclear whether actual behavior of different user types matches theoretical conjectures and how user typologiescan drive successful gamification design in sustainability contexts. This work addresses this gap by evaluating the design of a gamified app for sustainability at work by comparing expert evaluation (n=10) and analysis of actual user behavior (n=37) of different Hexad player types over a two-month period. In juxtaposing expert opinions and user behavior, our results reveal that actual user behavior greatly differs from expert suggestions and theoretical assumptions. Our results contribute to future research on tailored gamification by questioning the current state of tailored design theory mainly driven by self-report and pointing to the relevance of the context and non-stereotypical approaches for future personalization efforts.