I recently made my first significant contribution to the ongoing Z, T, R saga, which I urge you to read and consider here. Though it was posted on another source, I thought it was significant enough that I did not want GEB readers to miss out on the discussion.
In short, I feel that while Z, T, and R are not my favorite thing to ever happen to the real estate industry, we should be content that they are what they are and not a brokerage, which would directly compete with us. I argue that I would rather have them be marketing companies than be another RedFin and compete directly for commission dollars. Give it a read and see what you think.