I’ve been using adaptive AA frequently for the past 4-5 years. I have a client who is really concerned about sharpness and so I converted to adaptive for those projects. As it turned out adaptive worked very well and rarely produced flicker so I have made it my default setting. Most projects are HD so as Juan suggested that makes sharpness more critical and may solve some of the aliasing issues too. On the occasion I do have an issu , I may render on oversample for that element on those occasions.
Oddly enough I have found that if I’m compositing into existing live film or video oversample often seems to work better. As it turns out live media (film/video and even still photography) is often very soft compared to CG. Depending upon the source sometimes extremely soft. I find that oversample often works well for this.
Aggressive bump maps are usually the most problematic thing when using the adaptive setting so I try to pull back my bump maps if they fizzle in tests. If I need bump maps of a particular setting and I have a big move that brings the noise frequency of the bump too close to the pixel resolution of the frame I will sometimes run separate passes with different bump settings on the same object. I can selectively transition the passes in and out in the composite to control fizzle while still using adaptive.
Hope this is useful.