I'm not familiar with them, however two things I note: Their auditor training isn't to RABQSA or IRCA requirements - so you should review how they transfer the necessary skills and, they claim:
Worldwide Course Recognition:
CALISO online training courses are recognized by all registrars and hiring companies as objective evidence of effective training on the particular standard and regulation.
I've spent over 20 years in the industry, as a competitor, and I've never heard of them! I don't know how they can claim "recognition" by all registrars...
They claim:
Since 1999, they have been the most popular and most widely used training courses in English, with over 15,000 trainees in the US and worldwide.
Compared to what? There are far more experienced organization who had more than 10 years start on this!
They claim:
"All the theoretical aspects of auditing are covered according to the guidelines of RAB (Registrar Acation Board)."
But the actual course isn't accredited! It's only the theoretical aspects? Meets the guidelines? Who says?
IMHO - there are better places to learn how to audit.