I am facing a problem of choosing LOR from two prof. One is Canadian and kind of well know, but I just took a course with him and he does not know me well. He told me that he can only write about my good grad, competitive scholarship and community service, which is basically what I write in my CV. Another one is a prof in a Chinese institution where I did undergrad. I took a course of comprehensive experiment with her and did very good jobs. She can write a very strong letter about my performance, although still not about research.
I have already have two very strong LoR from Canadians all related with research, but for the third one, I have no other choice. As you may know, Chinese LoR has very bad reputation. On the other hand, the Canadian prof told me that anything other than enthusiastic endorsement would sink me for top program. Do you think it really the case? I am thinking that the Chinese one is enthusiastic, so at least it won't hurt me, they just ignore it. The Canadian one can at least convey something good about me, but would it really heart me if it is plain? All opinions would be appreciated! Thank you!