A cognitive evaluation of a sample of first wave of ambient intelligent prototypes was used to identify key implications for universal access in ambient intelligence environments, using a simple model of cognitive factors (Simplex Two). Emotional aspects of the user experience were the least well developed. A study of user experience, with two intelligent prototypes, one less intelligent and irritating showed a substantial impact of negative emotions on user performance that was independent of age. Surprising, performance changed significantly but ratings of perceived difficulty did not, suggesting caution in their uses. Finally, a case study of the user-participative development of a PDA for use with ambient intelligence confirmed the importance of emotional factors in inclusive design. Clearly, well structured and systematic methodologies (e.g. UUID) can consider the users’ emotional experience and inform the construction of ambient intelligence prototypes and systems.