I have the 4047 and I haven't heard the ST79. That being said, if I had to do it over again and for some reason pick between those two, I'd still pick the 4047. It's a great, well regarded mic. You can feel good about having it for a lifetime of recording. On the other hand, if you do end up wanting to sell either one, the reputation, production history and widespread understanding of what a 4047 is will improve its resale value in both the near and far future.
I don't know if that will be true about the ST79. I'd be curious to hear if folks think this one is a potential low-end classic. If so, then good to know!
If it's the multi-pattern aspect that draws you, consider buying a good cardioid, then save a little extra for a CAD M179, which by most accounts seems to be a great deal on an entry level multi-pattern. If I were doing it all over again, I might also think about an Oktavamod 319.