A Google Map is typically one of those ‘authority’ recommendations Google usually likes but yes I can see that it might be difficult for many site owners to include that bit of JS on their site and potentially see some slight speed issues.

While this is not a particular test I have run myself (a focused, singular test of using an image vs Google Map embed) my recommendation for you to do is to use an image for the pages you are worried about and perhaps use the actual Map code on a page you are not so worried about, like the About page? That way the speed issues aren’t there on the pages you need to render as fast as possible but your site gets the potential ranking signal value from having the embed code on another page on your website. You get the best of both.