What is the difference of hosting it via the sites you have recommended versus Google Hangouts?

I would say try both. Kind of personal preference. I used meeting burner first. Then I did everything on Google hangouts for awhile.

Obviously the big benefit to hangouts are the fast that they are free. Meeting burner has some features not found anywhere else like the temparature gauge, hosted replays and one-click uploading to youtube.

I have tested both. It seems like I got higher optin rates on the simple webinar registration page. But I am constantly testing and tweaking to see what is best.