If you pick the right type of anemone it's not a problem at all in a mixed reef.
Sand dwellers like LTA and Malu make it easy to keep from corals on rockwork.
Magnifica are known to pretty much stay put if given a perch high up on rock so they can reach for max light, and that is my personal favorite and what I keep.
Anemone's and clowns are what got me into this hobby in the first place some 33 years ago, I can't imagine having a tank w/out them.