The funding makes a huge difference. A student that the advisor doesn't have to fund that has initiative and workable ideas will only require occasional face time. To top it off, the ones I've seen that were like this were usually more senior, coming from some experience usually in the industry, and as a result more savvy; therefore they knew what leverage they had and were able to walk away from bad situations. But an RA that gets paid out of grant money will have a lot less leverage.