Portfolios have attracted considerable interest among ESL writing and assessment specialists since the 1980s. Whether they have fulfilled the promise their proponents envision is a question still under investigation. This paper describes two case studies which looked at student experiences with portfolios in two ESL writing courses where the portfolio pedagogies employed differed, so that each student was able to experience portfolios under meaningful conditions for comparison. The results showed that the participants liked the idea of portfolios but did not strongly endorse their use as employed in the courses which served as the research settings. The study's findings shed light on how students respond to different portfolio models and thus contribute to our understanding of the place portfolios can occupy in L2 writing instruction.