In China, memorizing model texts from various sources including textbooks and other reference books is usually considered a legitimate learning practice by both teachers and students, especially when the students are preparing for high-stakes language tests, such as IELTS (International English Language Testing System). However, very little linguistic research has been done on the pedagogical values of these model texts. This study, therefore, aims to address this gap by investigating 15 model essays collected from three commercial exam preparation books for IELTS in mainland China. Drawing on analytical tools based on Systemic Functional Linguistics, a linguistic analysis is conducted to examine the lexicogrammatical resources pertaining to the realization of interpersonal meanings, such as "Engagement" resources in the texts. Results suggest that the "Engagement" resources valued in the model essays reflect the local rhetorical style in constructing an English argumentative text and it is argued that, while the texts may be effective in helping students acquire higher scores on a language test, namely the IELTS writing component, they do not provide enough access to the linguistic resources that are valued beyond the context of language testing.