all have their respecive place in woodworking and construction. I personally feel that mdf is great for shelving and other structural things that are away from water.
I do like real wood furniture and always strive to buy only that, but we purchased a coffee table that was great and fitted in with our furniture. We got it and upon inspection at home, I noticed that the underneath was mdf. I was amazed at how the finish looked sooo much like real wood.
I do shutter when someone puts a sweating glass on the table without a coaster.
This stuff dissolves when in contact with water on a chip or open area, be careful.