This paper reports on a mixed-methods study delving into EFL students' experiences and perspectives on a text-based pedagogical chatbot. Utilizing chatbot-mediated interaction, a questionnaire survey, and focus group discussions, the study centers around the cognitive and affective domains of learning in relation to the chatbot's affordances and limitations. Additionally, it investigates potential associations between L2 proficiency and perceptions on the chatbot. The sample (n = 143) consisted of undergraduate students from a Saudi university who engaged in guided and self-initiated interactions with the chatbot. By and large, the findings point to positive experiences concerning the chatbot's intelligibility and comprehension. In terms of the interaction, the chatbot is perceived as supportive of L2 practice and writing development, interest-provoking, enhancing motivation, and alleviating writing anxiety. Contrastingly, certain demotivating factors are reported regarding the chatbot's interactional and instructional abilities, including the lack of extended conversations, sensitivity to inaccurate language forms, and sporadic irrelevant responses. Moreover, the Mann-Whitney U test reveals that L2 proficiency does not affect overall views on the chatbot-mediated interaction, except for the aspect of usefulness for L2 practice, which has significantly more positive views from high-intermediate students. Pedagogical implications pertinent to the integration of chatbots in L2 learning are discussed.