How to know if the ICNAAM conference is good?

I have received an invitation to participate in a symposium within the International Conference of Numerical Analysis and Applied Mathematics (link). The symposium is organized by a professor that is respected on my field, but I have my doubts about the conference itself. Besides my research field (statistics) and the scope of the conference have little in common.

The problem is that I have never heard before about that conference to any colleague in my field, if we exclude the spam emails sent by the conference organizers asking researchers to attend or to organize a symposium within the conference.

I am asking for your previous experiences with this conference (if any) or about your academic opinions of it. Specifically: is it a good enough/respectable conference? is it a well known conference in the field of Numerical Analysis/Applied Mathematics?