Where Soundtoys are the industry standard to audio effects. Fabfilter is the best toolkit a producer can have to control his audio. So many amazing options are available now in a great sounding way, I already mixed my last few mixes WAY faster than I did before.
The Pro bundle gives you all the plugins you need to shape your mixes the way you want. The best EQ, compressor, multiband compressor, limiter, gate, de-esser and adjustable reverb I can think of.
I'll be teaching with this bundle and the soundtoys one. My students can buy these bundles with the same 50% discount which will give them a big edge starting mixing music!!