Extension Course Professor LOR

[lizlizliz]

I received a double BA in Psychology and Sociology in 2013. I am applying for MFT and School Psychology grad school programs. I have at least 2 strong professional references from post-grad work experience. However, the LOR from an academic source keeps me up at night...

I did not anticipate going to graduate school so I did not get close to any of my professors. I have reached out to multiple professors and have gotten rejected each time. One professor was willing to say "I was in the class and received an A", a weak LOR. I have taken a relevant UC Berkeley extension course and can receive a letter from my teacher who is a PhD/LMFT, respected in the field. Which academic letter will carry more weight? An extremely weak LOR from a professor from my undergrad institution that barely remembers me or a stellar LOR from someone in the field who can praise me in the academic context?

Please help! 

[TakeruK]

What kind of course is the Berkeley extension course? Is it equivalent to a course that would be part of a BA curriculum? If so, I'd definitely go with this LOR.

If not, then it would depend on a lot more things. You say this LOR would be stellar---what makes it stellar and different than the "I was in the class and received an A" letter from your own school?