Three-finger zoom is more inconvenient and a little inconsistent in my experience on iOS9.  It is inconvenient in that scrolling a page is sometimes difficult to accomplish when zoomed in.  I feel like three-finger zoom is a last resort for when something is not properly accessible.  I am visually handicapped and being able to zoom is essential for me.  I have a hard time using sites that disable zoom already, this is only going to exacerbate the problem.